commit 0d92295142c50a82eab8baf5bf0e7f0f6ecbf308
Author: Sangbum Kim <sangbumkim@amuz.es>
Date:   Mon Nov 6 22:24:08 2017 +0900

    initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..1565f94
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,120 @@
+
+# Created by https://www.gitignore.io/api/intellij,go,linux,osx,windows
+
+### Intellij ###
+# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and Webstorm
+# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
+
+.idea
+*.iml
+
+## File-based project format:
+*.ipr
+*.iws
+
+## Plugin-specific files:
+
+# IntelliJ
+/out/
+
+# mpeltonen/sbt-idea plugin
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Crashlytics plugin (for Android Studio and IntelliJ)
+com_crashlytics_export_strings.xml
+crashlytics.properties
+crashlytics-build.properties
+fabric.properties
+
+
+### Go ###
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test
+*.prof
+
+
+### Linux ###
+*~
+*.swp
+
+# temporary files which can be created if a process still has a handle open of a deleted file
+.fuse_hidden*
+
+# KDE directory preferences
+.directory
+
+# Linux trash folder which might appear on any partition or disk
+.Trash-*
+
+
+### OSX ###
+.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must end with two \r
+Icon
+
+
+# Thumbnails
+._*
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+
+
+### Windows ###
+# Windows image file caches
+Thumbs.db
+ehthumbs.db
+
+# Folder config file
+Desktop.ini
+
+# Recycle Bin used on file shares
+$RECYCLE.BIN/
+
+# Windows Installer files
+*.cab
+*.msi
+*.msm
+*.msp
+
+# Windows shortcuts
+*.lnk
diff --git a/Gopkg.lock b/Gopkg.lock
new file mode 100644
index 0000000..2c521ba
--- /dev/null
+++ b/Gopkg.lock
@@ -0,0 +1,33 @@
+# This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
+
+
+[[projects]]
+  name = "go.uber.org/atomic"
+  packages = ["."]
+  revision = "4e336646b2ef9fc6e47be8e21594178f98e5ebcf"
+  version = "v1.2.0"
+
+[[projects]]
+  name = "go.uber.org/multierr"
+  packages = ["."]
+  revision = "3c4937480c32f4c13a875a1829af76c98ca3d40a"
+  version = "v1.1.0"
+
+[[projects]]
+  name = "go.uber.org/zap"
+  packages = [".","buffer","internal/bufferpool","internal/color","internal/exit","zapcore"]
+  revision = "35aad584952c3e7020db7b839f6b102de6271f89"
+  version = "v1.7.1"
+
+[[projects]]
+  name = "gopkg.in/natefinch/lumberjack.v2"
+  packages = ["."]
+  revision = "a96e63847dc3c67d17befa69c303767e2f84e54f"
+  version = "v2.1"
+
+[solve-meta]
+  analyzer-name = "dep"
+  analyzer-version = 1
+  inputs-digest = "4e56bae68db45690431363f15d1dcc7b8a412c4522bab27b460e3f0797d4b1f1"
+  solver-name = "gps-cdcl"
+  solver-version = 1
diff --git a/Gopkg.toml b/Gopkg.toml
new file mode 100644
index 0000000..e3acfd6
--- /dev/null
+++ b/Gopkg.toml
@@ -0,0 +1,30 @@
+
+# Gopkg.toml example
+#
+# Refer to https://github.com/golang/dep/blob/master/docs/Gopkg.toml.md
+# for detailed Gopkg.toml documentation.
+#
+# required = ["github.com/user/thing/cmd/thing"]
+# ignored = ["github.com/user/project/pkgX", "bitbucket.org/user/project/pkgA/pkgY"]
+#
+# [[constraint]]
+#   name = "github.com/user/project"
+#   version = "1.0.0"
+#
+# [[constraint]]
+#   name = "github.com/user/project2"
+#   branch = "dev"
+#   source = "github.com/myfork/project2"
+#
+# [[override]]
+#  name = "github.com/x/y"
+#  version = "2.4.0"
+
+
+[[constraint]]
+  name = "go.uber.org/zap"
+  version = "1.7.1"
+
+[[constraint]]
+  name = "gopkg.in/natefinch/lumberjack.v2"
+  version = "2.1.0"
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..ae350db
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,6 @@
+# Builds the project
+setup:
+	go get -u github.com/golang/dep/cmd/dep
+	${GOPATH}/bin/dep ensure -v
+
+.PHONY: clean install
diff --git a/rotater/global.go b/rotater/global.go
new file mode 100644
index 0000000..7162c3f
--- /dev/null
+++ b/rotater/global.go
@@ -0,0 +1,51 @@
+package rotater
+
+import (
+	"os"
+	"path"
+	"log"
+)
+
+var loggers RotateSyncerSet
+
+func NewLogWriter(FileName string, MaxSizeMb, MaxBackup, MaxDay int, logDir string) RotateSyncer {
+	switch FileName {
+	case "Stdout":
+		return newLocked(os.Stdout)
+	case "Stderr":
+		return newLocked(os.Stderr)
+	default:
+		logpath := FileName
+		if logDir != "" {
+			logpath = path.Join(logDir, FileName)
+		}
+
+		log.Println(" Attention!! log writes to ", logpath)
+
+		logWriter := newRotater(
+			logpath,
+			MaxSizeMb, // megabytes
+			MaxBackup,
+			MaxDay, //days
+		)
+		loggers.Store(logWriter)
+		logWriter.SetOnClose(func() { loggers.Delete(logWriter) })
+		return logWriter
+	}
+}
+
+func Rotate() {
+	loggers.Range(func(rotater RotateSyncer) {
+		rotater.Sync()
+		rotater.Rotate()
+	})
+	log.Println("rotated")
+}
+
+func Close() {
+	loggers.Range(func(rotater RotateSyncer) {
+		rotater.Sync()
+		rotater.Close()
+	})
+	log.Println("end of log")
+}
diff --git a/rotater/set_logcore.go b/rotater/set_logcore.go
new file mode 100644
index 0000000..82fb0c0
--- /dev/null
+++ b/rotater/set_logcore.go
@@ -0,0 +1,46 @@
+package rotater
+
+import (
+	"sync"
+	"sync/atomic"
+)
+
+/**
+logger set
+ */
+type RotateSyncerSet struct {
+	storage sync.Map
+}
+
+func (s *RotateSyncerSet) Delete(key RotateSyncer) {
+	s.storage.Delete(key)
+}
+func (s *RotateSyncerSet) Exist(key RotateSyncer) (ok bool) {
+	_, ok = s.storage.Load(key)
+	return
+}
+func (s *RotateSyncerSet) SetNx(key RotateSyncer) (bool) {
+	_, exist := s.storage.LoadOrStore(key, 0)
+	return !exist
+}
+func (s *RotateSyncerSet) Range(f func(key RotateSyncer)) {
+	s.storage.Range(s.rangeWrap(f))
+}
+func (s *RotateSyncerSet) Store(key RotateSyncer) {
+	s.storage.Store(key, 0)
+}
+func (s *RotateSyncerSet) rangeWrap(f func(key RotateSyncer)) func(key, value interface{}) bool {
+	ok := true
+	return func(key, value interface{}) bool {
+		f(key.(RotateSyncer))
+		return ok
+	}
+}
+
+func (s *RotateSyncerSet) Len() int {
+	var count uint64
+	s.Range(func(conn RotateSyncer) {
+		atomic.AddUint64(&count, 1)
+	})
+	return int(count)
+}
diff --git a/rotater/wrapped.go b/rotater/wrapped.go
new file mode 100644
index 0000000..43f7f31
--- /dev/null
+++ b/rotater/wrapped.go
@@ -0,0 +1,38 @@
+package rotater
+
+import (
+	"sync"
+)
+
+type LockedWriteSyncer struct {
+	sync.Mutex
+	ws WriteSyncer
+}
+
+// Lock wraps a WriteSyncer in a mutex to make it safe for concurrent use. In
+// particular, *os.Files must be locked before use.
+func newLocked(ws WriteSyncer) RotateSyncer {
+	if lws, ok := ws.(*LockedWriteSyncer); ok {
+		// no need to layer on another lock
+		return lws
+	}
+	return &LockedWriteSyncer{ws: ws}
+}
+
+func (s *LockedWriteSyncer) Write(bs []byte) (int, error) {
+	s.Lock()
+	n, err := s.ws.Write(bs)
+	s.Unlock()
+	return n, err
+}
+
+func (s *LockedWriteSyncer) Sync() error {
+	s.Lock()
+	err := s.ws.Sync()
+	s.Unlock()
+	return err
+}
+
+func (r *LockedWriteSyncer) SetOnClose(closeFunc CloseFunc) {}
+func (r *LockedWriteSyncer) Rotate() (err error)            { return }
+func (r *LockedWriteSyncer) Close() (err error)             { return }
diff --git a/rotater/writeRotater.go b/rotater/writeRotater.go
new file mode 100644
index 0000000..9583d7e
--- /dev/null
+++ b/rotater/writeRotater.go
@@ -0,0 +1,66 @@
+package rotater
+
+import (
+	"gopkg.in/natefinch/lumberjack.v2"
+	"io"
+	"sync"
+)
+
+type CloseFunc func()
+
+type WriteSyncer interface {
+	io.Writer
+	Sync() error
+}
+
+type RotateSyncer interface {
+	io.WriteCloser
+	SetOnClose(CloseFunc)
+	Rotate() error
+	Sync() error
+}
+
+type rotateSyncer struct {
+	setOnceOnclose *sync.Once
+	onClose        CloseFunc
+	lumberjack.Logger
+}
+
+func newRotater(filename string, maxSize, maxBackup, maxDay int) RotateSyncer {
+	return &rotateSyncer{
+		setOnceOnclose: &sync.Once{},
+		Logger: lumberjack.Logger{
+			Filename:   filename,
+			MaxSize:    maxSize, // megabytes
+			MaxBackups: maxBackup,
+			MaxAge:     maxDay, //days
+			LocalTime:  false,
+			Compress:   false,
+		},
+	}
+}
+func (r *rotateSyncer) SetOnClose(closeFunc CloseFunc) {
+	r.setOnceOnclose.Do(func() {
+		r.onClose = closeFunc
+	})
+}
+
+func (r *rotateSyncer) Rotate() error {
+	return r.Logger.Rotate()
+}
+func (r *rotateSyncer) Close() error {
+	defer func() {
+		if r.onClose != nil {
+			r.onClose()
+		}
+	}()
+	return r.Logger.Close()
+}
+
+func (r *rotateSyncer) Sync() error {
+	return nil
+}
+
+func (s *rotateSyncer) Write(bs []byte) (int, error) {
+	return s.Logger.Write(bs)
+}
diff --git a/vendor/go.uber.org/atomic/.github/PULL_REQUEST_TEMPLATE.md b/vendor/go.uber.org/atomic/.github/PULL_REQUEST_TEMPLATE.md
new file mode 100644
index 0000000..8ef55f8
--- /dev/null
+++ b/vendor/go.uber.org/atomic/.github/PULL_REQUEST_TEMPLATE.md
@@ -0,0 +1,8 @@
+Before opening your pull request, please make sure that you've:
+
+- [ ] [signed Uber's Contributor License Agreement](https://docs.google.com/a/uber.com/forms/d/1pAwS_-dA1KhPlfxzYLBqK6rsSWwRwH95OCCZrcsY5rk/viewform);
+- [ ] added tests to cover your changes;
+- [ ] run the test suite locally (`make test`); and finally,
+- [ ] run the linters locally (`make lint`).
+
+Thanks for your contribution!
diff --git a/vendor/go.uber.org/atomic/.gitignore b/vendor/go.uber.org/atomic/.gitignore
new file mode 100644
index 0000000..0a4504f
--- /dev/null
+++ b/vendor/go.uber.org/atomic/.gitignore
@@ -0,0 +1,11 @@
+.DS_Store
+/vendor
+/cover
+cover.out
+lint.log
+
+# Binaries
+*.test
+
+# Profiling output
+*.prof
diff --git a/vendor/go.uber.org/atomic/.travis.yml b/vendor/go.uber.org/atomic/.travis.yml
new file mode 100644
index 0000000..f1ce95a
--- /dev/null
+++ b/vendor/go.uber.org/atomic/.travis.yml
@@ -0,0 +1,21 @@
+sudo: false
+language: go
+go_import_path: go.uber.org/atomic
+
+go:
+  - 1.5
+  - 1.6
+  - tip
+
+cache:
+  directories:
+    - vendor
+
+install:
+  - make install_ci
+
+script:
+  - make test_ci
+  - scripts/test-ubergo.sh
+  - make lint
+  - travis_retry goveralls -coverprofile=cover.out -service=travis-ci
diff --git a/vendor/go.uber.org/atomic/LICENSE.txt b/vendor/go.uber.org/atomic/LICENSE.txt
new file mode 100644
index 0000000..8765c9f
--- /dev/null
+++ b/vendor/go.uber.org/atomic/LICENSE.txt
@@ -0,0 +1,19 @@
+Copyright (c) 2016 Uber Technologies, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/vendor/go.uber.org/atomic/Makefile b/vendor/go.uber.org/atomic/Makefile
new file mode 100644
index 0000000..dfc63d9
--- /dev/null
+++ b/vendor/go.uber.org/atomic/Makefile
@@ -0,0 +1,64 @@
+PACKAGES := $(shell glide nv)
+# Many Go tools take file globs or directories as arguments instead of packages.
+PACKAGE_FILES ?= *.go
+
+
+# The linting tools evolve with each Go version, so run them only on the latest
+# stable release.
+GO_VERSION := $(shell go version | cut -d " " -f 3)
+GO_MINOR_VERSION := $(word 2,$(subst ., ,$(GO_VERSION)))
+LINTABLE_MINOR_VERSIONS := 7 8
+ifneq ($(filter $(LINTABLE_MINOR_VERSIONS),$(GO_MINOR_VERSION)),)
+SHOULD_LINT := true
+endif
+
+
+export GO15VENDOREXPERIMENT=1
+
+
+.PHONY: build
+build:
+	go build -i $(PACKAGES)
+
+
+.PHONY: install
+install:
+	glide --version || go get github.com/Masterminds/glide
+	glide install
+
+
+.PHONY: test
+test:
+	go test -cover -race $(PACKAGES)
+
+
+.PHONY: install_ci
+install_ci: install
+	go get github.com/wadey/gocovmerge
+	go get github.com/mattn/goveralls
+	go get golang.org/x/tools/cmd/cover
+ifdef SHOULD_LINT
+	go get github.com/golang/lint/golint
+endif
+
+.PHONY: lint
+lint:
+ifdef SHOULD_LINT
+	@rm -rf lint.log
+	@echo "Checking formatting..."
+	@gofmt -d -s $(PACKAGE_FILES) 2>&1 | tee lint.log
+	@echo "Checking vet..."
+	@$(foreach dir,$(PACKAGE_FILES),go tool vet $(dir) 2>&1 | tee -a lint.log;)
+	@echo "Checking lint..."
+	@$(foreach dir,$(PKGS),golint $(dir) 2>&1 | tee -a lint.log;)
+	@echo "Checking for unresolved FIXMEs..."
+	@git grep -i fixme | grep -v -e vendor -e Makefile | tee -a lint.log
+	@[ ! -s lint.log ]
+else
+	@echo "Skipping linters on" $(GO_VERSION)
+endif
+
+
+.PHONY: test_ci
+test_ci: install_ci build
+	./scripts/cover.sh $(shell go list $(PACKAGES))
diff --git a/vendor/go.uber.org/atomic/README.md b/vendor/go.uber.org/atomic/README.md
new file mode 100644
index 0000000..bb4a12c
--- /dev/null
+++ b/vendor/go.uber.org/atomic/README.md
@@ -0,0 +1,34 @@
+# atomic [![GoDoc][doc-img]][doc] [![Build Status][ci-img]][ci] [![Coverage Status][cov-img]][cov]
+
+Simple wrappers for primitive types to enforce atomic access.
+
+## Installation
+`go get -u go.uber.org/atomic`
+
+## Usage
+The standard library's `sync/atomic` is powerful, but it's easy to forget which
+variables must be accessed atomically. `go.uber.org/atomic` preserves all the
+functionality of the standard library, but wraps the primitive types to
+provide a safer, more convenient API.
+
+```go
+var atom atomic.Uint32
+atom.Store(42)
+atom.Sub(2)
+atom.CAS(40, 11)
+```
+
+See the [documentation][doc] for a complete API specification.
+
+## Development Status
+Stable.
+
+<hr>
+Released under the [MIT License](LICENSE.txt).
+
+[doc-img]: https://godoc.org/github.com/uber-go/atomic?status.svg
+[doc]: https://godoc.org/go.uber.org/atomic
+[ci-img]: https://travis-ci.org/uber-go/atomic.svg?branch=master
+[ci]: https://travis-ci.org/uber-go/atomic
+[cov-img]: https://coveralls.io/repos/github/uber-go/atomic/badge.svg?branch=master
+[cov]: https://coveralls.io/github/uber-go/atomic?branch=master
diff --git a/vendor/go.uber.org/atomic/atomic.go b/vendor/go.uber.org/atomic/atomic.go
new file mode 100644
index 0000000..290b884
--- /dev/null
+++ b/vendor/go.uber.org/atomic/atomic.go
@@ -0,0 +1,304 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Package atomic provides simple wrappers around numerics to enforce atomic
+// access.
+package atomic
+
+import (
+	"math"
+	"sync/atomic"
+)
+
+// Int32 is an atomic wrapper around an int32.
+type Int32 struct{ v int32 }
+
+// NewInt32 creates an Int32.
+func NewInt32(i int32) *Int32 {
+	return &Int32{i}
+}
+
+// Load atomically loads the wrapped value.
+func (i *Int32) Load() int32 {
+	return atomic.LoadInt32(&i.v)
+}
+
+// Add atomically adds to the wrapped int32 and returns the new value.
+func (i *Int32) Add(n int32) int32 {
+	return atomic.AddInt32(&i.v, n)
+}
+
+// Sub atomically subtracts from the wrapped int32 and returns the new value.
+func (i *Int32) Sub(n int32) int32 {
+	return atomic.AddInt32(&i.v, -n)
+}
+
+// Inc atomically increments the wrapped int32 and returns the new value.
+func (i *Int32) Inc() int32 {
+	return i.Add(1)
+}
+
+// Dec atomically decrements the wrapped int32 and returns the new value.
+func (i *Int32) Dec() int32 {
+	return i.Sub(1)
+}
+
+// CAS is an atomic compare-and-swap.
+func (i *Int32) CAS(old, new int32) bool {
+	return atomic.CompareAndSwapInt32(&i.v, old, new)
+}
+
+// Store atomically stores the passed value.
+func (i *Int32) Store(n int32) {
+	atomic.StoreInt32(&i.v, n)
+}
+
+// Swap atomically swaps the wrapped int32 and returns the old value.
+func (i *Int32) Swap(n int32) int32 {
+	return atomic.SwapInt32(&i.v, n)
+}
+
+// Int64 is an atomic wrapper around an int64.
+type Int64 struct{ v int64 }
+
+// NewInt64 creates an Int64.
+func NewInt64(i int64) *Int64 {
+	return &Int64{i}
+}
+
+// Load atomically loads the wrapped value.
+func (i *Int64) Load() int64 {
+	return atomic.LoadInt64(&i.v)
+}
+
+// Add atomically adds to the wrapped int64 and returns the new value.
+func (i *Int64) Add(n int64) int64 {
+	return atomic.AddInt64(&i.v, n)
+}
+
+// Sub atomically subtracts from the wrapped int64 and returns the new value.
+func (i *Int64) Sub(n int64) int64 {
+	return atomic.AddInt64(&i.v, -n)
+}
+
+// Inc atomically increments the wrapped int64 and returns the new value.
+func (i *Int64) Inc() int64 {
+	return i.Add(1)
+}
+
+// Dec atomically decrements the wrapped int64 and returns the new value.
+func (i *Int64) Dec() int64 {
+	return i.Sub(1)
+}
+
+// CAS is an atomic compare-and-swap.
+func (i *Int64) CAS(old, new int64) bool {
+	return atomic.CompareAndSwapInt64(&i.v, old, new)
+}
+
+// Store atomically stores the passed value.
+func (i *Int64) Store(n int64) {
+	atomic.StoreInt64(&i.v, n)
+}
+
+// Swap atomically swaps the wrapped int64 and returns the old value.
+func (i *Int64) Swap(n int64) int64 {
+	return atomic.SwapInt64(&i.v, n)
+}
+
+// Uint32 is an atomic wrapper around an uint32.
+type Uint32 struct{ v uint32 }
+
+// NewUint32 creates a Uint32.
+func NewUint32(i uint32) *Uint32 {
+	return &Uint32{i}
+}
+
+// Load atomically loads the wrapped value.
+func (i *Uint32) Load() uint32 {
+	return atomic.LoadUint32(&i.v)
+}
+
+// Add atomically adds to the wrapped uint32 and returns the new value.
+func (i *Uint32) Add(n uint32) uint32 {
+	return atomic.AddUint32(&i.v, n)
+}
+
+// Sub atomically subtracts from the wrapped uint32 and returns the new value.
+func (i *Uint32) Sub(n uint32) uint32 {
+	return atomic.AddUint32(&i.v, ^(n - 1))
+}
+
+// Inc atomically increments the wrapped uint32 and returns the new value.
+func (i *Uint32) Inc() uint32 {
+	return i.Add(1)
+}
+
+// Dec atomically decrements the wrapped int32 and returns the new value.
+func (i *Uint32) Dec() uint32 {
+	return i.Sub(1)
+}
+
+// CAS is an atomic compare-and-swap.
+func (i *Uint32) CAS(old, new uint32) bool {
+	return atomic.CompareAndSwapUint32(&i.v, old, new)
+}
+
+// Store atomically stores the passed value.
+func (i *Uint32) Store(n uint32) {
+	atomic.StoreUint32(&i.v, n)
+}
+
+// Swap atomically swaps the wrapped uint32 and returns the old value.
+func (i *Uint32) Swap(n uint32) uint32 {
+	return atomic.SwapUint32(&i.v, n)
+}
+
+// Uint64 is an atomic wrapper around a uint64.
+type Uint64 struct{ v uint64 }
+
+// NewUint64 creates a Uint64.
+func NewUint64(i uint64) *Uint64 {
+	return &Uint64{i}
+}
+
+// Load atomically loads the wrapped value.
+func (i *Uint64) Load() uint64 {
+	return atomic.LoadUint64(&i.v)
+}
+
+// Add atomically adds to the wrapped uint64 and returns the new value.
+func (i *Uint64) Add(n uint64) uint64 {
+	return atomic.AddUint64(&i.v, n)
+}
+
+// Sub atomically subtracts from the wrapped uint64 and returns the new value.
+func (i *Uint64) Sub(n uint64) uint64 {
+	return atomic.AddUint64(&i.v, ^(n - 1))
+}
+
+// Inc atomically increments the wrapped uint64 and returns the new value.
+func (i *Uint64) Inc() uint64 {
+	return i.Add(1)
+}
+
+// Dec atomically decrements the wrapped uint64 and returns the new value.
+func (i *Uint64) Dec() uint64 {
+	return i.Sub(1)
+}
+
+// CAS is an atomic compare-and-swap.
+func (i *Uint64) CAS(old, new uint64) bool {
+	return atomic.CompareAndSwapUint64(&i.v, old, new)
+}
+
+// Store atomically stores the passed value.
+func (i *Uint64) Store(n uint64) {
+	atomic.StoreUint64(&i.v, n)
+}
+
+// Swap atomically swaps the wrapped uint64 and returns the old value.
+func (i *Uint64) Swap(n uint64) uint64 {
+	return atomic.SwapUint64(&i.v, n)
+}
+
+// Bool is an atomic Boolean.
+type Bool struct{ v uint32 }
+
+// NewBool creates a Bool.
+func NewBool(initial bool) *Bool {
+	return &Bool{boolToInt(initial)}
+}
+
+// Load atomically loads the Boolean.
+func (b *Bool) Load() bool {
+	return truthy(atomic.LoadUint32(&b.v))
+}
+
+// Store atomically stores the passed value.
+func (b *Bool) Store(new bool) {
+	atomic.StoreUint32(&b.v, boolToInt(new))
+}
+
+// Swap sets the given value and returns the previous value.
+func (b *Bool) Swap(new bool) bool {
+	return truthy(atomic.SwapUint32(&b.v, boolToInt(new)))
+}
+
+// Toggle atomically negates the Boolean and returns the previous value.
+func (b *Bool) Toggle() bool {
+	return truthy(atomic.AddUint32(&b.v, 1) - 1)
+}
+
+func truthy(n uint32) bool {
+	return n&1 == 1
+}
+
+func boolToInt(b bool) uint32 {
+	if b {
+		return 1
+	}
+	return 0
+}
+
+// Float64 is an atomic wrapper around float64.
+type Float64 struct {
+	v uint64
+}
+
+// NewFloat64 creates a Float64.
+func NewFloat64(f float64) *Float64 {
+	return &Float64{math.Float64bits(f)}
+}
+
+// Load atomically loads the wrapped value.
+func (f *Float64) Load() float64 {
+	return math.Float64frombits(atomic.LoadUint64(&f.v))
+}
+
+// Store atomically stores the passed value.
+func (f *Float64) Store(s float64) {
+	atomic.StoreUint64(&f.v, math.Float64bits(s))
+}
+
+// Add atomically adds to the wrapped float64 and returns the new value.
+func (f *Float64) Add(s float64) float64 {
+	for {
+		old := f.Load()
+		new := old + s
+		if f.CAS(old, new) {
+			return new
+		}
+	}
+}
+
+// Sub atomically subtracts from the wrapped float64 and returns the new value.
+func (f *Float64) Sub(s float64) float64 {
+	return f.Add(-s)
+}
+
+// CAS is an atomic compare-and-swap.
+func (f *Float64) CAS(old, new float64) bool {
+	return atomic.CompareAndSwapUint64(&f.v, math.Float64bits(old), math.Float64bits(new))
+}
+
+// Value shadows the type of the same name from sync/atomic
+// https://godoc.org/sync/atomic#Value
+type Value struct{ atomic.Value }
diff --git a/vendor/go.uber.org/atomic/atomic_test.go b/vendor/go.uber.org/atomic/atomic_test.go
new file mode 100644
index 0000000..284f786
--- /dev/null
+++ b/vendor/go.uber.org/atomic/atomic_test.go
@@ -0,0 +1,147 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package atomic
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestInt32(t *testing.T) {
+	atom := NewInt32(42)
+
+	require.Equal(t, int32(42), atom.Load(), "Load didn't work.")
+	require.Equal(t, int32(46), atom.Add(4), "Add didn't work.")
+	require.Equal(t, int32(44), atom.Sub(2), "Sub didn't work.")
+	require.Equal(t, int32(45), atom.Inc(), "Inc didn't work.")
+	require.Equal(t, int32(44), atom.Dec(), "Dec didn't work.")
+
+	require.True(t, atom.CAS(44, 0), "CAS didn't report a swap.")
+	require.Equal(t, int32(0), atom.Load(), "CAS didn't set the correct value.")
+
+	require.Equal(t, int32(0), atom.Swap(1), "Swap didn't return the old value.")
+	require.Equal(t, int32(1), atom.Load(), "Swap didn't set the correct value.")
+
+	atom.Store(42)
+	require.Equal(t, int32(42), atom.Load(), "Store didn't set the correct value.")
+}
+
+func TestInt64(t *testing.T) {
+	atom := NewInt64(42)
+
+	require.Equal(t, int64(42), atom.Load(), "Load didn't work.")
+	require.Equal(t, int64(46), atom.Add(4), "Add didn't work.")
+	require.Equal(t, int64(44), atom.Sub(2), "Sub didn't work.")
+	require.Equal(t, int64(45), atom.Inc(), "Inc didn't work.")
+	require.Equal(t, int64(44), atom.Dec(), "Dec didn't work.")
+
+	require.True(t, atom.CAS(44, 0), "CAS didn't report a swap.")
+	require.Equal(t, int64(0), atom.Load(), "CAS didn't set the correct value.")
+
+	require.Equal(t, int64(0), atom.Swap(1), "Swap didn't return the old value.")
+	require.Equal(t, int64(1), atom.Load(), "Swap didn't set the correct value.")
+
+	atom.Store(42)
+	require.Equal(t, int64(42), atom.Load(), "Store didn't set the correct value.")
+}
+
+func TestUint32(t *testing.T) {
+	atom := NewUint32(42)
+
+	require.Equal(t, uint32(42), atom.Load(), "Load didn't work.")
+	require.Equal(t, uint32(46), atom.Add(4), "Add didn't work.")
+	require.Equal(t, uint32(44), atom.Sub(2), "Sub didn't work.")
+	require.Equal(t, uint32(45), atom.Inc(), "Inc didn't work.")
+	require.Equal(t, uint32(44), atom.Dec(), "Dec didn't work.")
+
+	require.True(t, atom.CAS(44, 0), "CAS didn't report a swap.")
+	require.Equal(t, uint32(0), atom.Load(), "CAS didn't set the correct value.")
+
+	require.Equal(t, uint32(0), atom.Swap(1), "Swap didn't return the old value.")
+	require.Equal(t, uint32(1), atom.Load(), "Swap didn't set the correct value.")
+
+	atom.Store(42)
+	require.Equal(t, uint32(42), atom.Load(), "Store didn't set the correct value.")
+}
+
+func TestUint64(t *testing.T) {
+	atom := NewUint64(42)
+
+	require.Equal(t, uint64(42), atom.Load(), "Load didn't work.")
+	require.Equal(t, uint64(46), atom.Add(4), "Add didn't work.")
+	require.Equal(t, uint64(44), atom.Sub(2), "Sub didn't work.")
+	require.Equal(t, uint64(45), atom.Inc(), "Inc didn't work.")
+	require.Equal(t, uint64(44), atom.Dec(), "Dec didn't work.")
+
+	require.True(t, atom.CAS(44, 0), "CAS didn't report a swap.")
+	require.Equal(t, uint64(0), atom.Load(), "CAS didn't set the correct value.")
+
+	require.Equal(t, uint64(0), atom.Swap(1), "Swap didn't return the old value.")
+	require.Equal(t, uint64(1), atom.Load(), "Swap didn't set the correct value.")
+
+	atom.Store(42)
+	require.Equal(t, uint64(42), atom.Load(), "Store didn't set the correct value.")
+}
+
+func TestBool(t *testing.T) {
+	atom := NewBool(false)
+	require.False(t, atom.Toggle(), "Expected swap to return previous value.")
+	require.True(t, atom.Load(), "Unexpected state after swap.")
+
+	atom.Store(false)
+	require.False(t, atom.Load(), "Unexpected state after store.")
+
+	prev := atom.Swap(false)
+	require.False(t, prev, "Expected Swap to return previous value.")
+
+	prev = atom.Swap(true)
+	require.False(t, prev, "Expected Swap to return previous value.")
+}
+
+func TestFloat64(t *testing.T) {
+	atom := NewFloat64(4.2)
+
+	require.Equal(t, float64(4.2), atom.Load(), "Load didn't work.")
+
+	require.True(t, atom.CAS(4.2, 0.5), "CAS didn't report a swap.")
+	require.Equal(t, float64(0.5), atom.Load(), "CAS didn't set the correct value.")
+	require.False(t, atom.CAS(0.0, 1.5), "CAS reported a swap.")
+
+	atom.Store(42.0)
+	require.Equal(t, float64(42.0), atom.Load(), "Store didn't set the correct value.")
+	require.Equal(t, float64(42.5), atom.Add(0.5), "Add didn't work.")
+	require.Equal(t, float64(42.0), atom.Sub(0.5), "Sub didn't work.")
+}
+
+func TestValue(t *testing.T) {
+	var v Value
+	assert.Nil(t, v.Load(), "initial Value is not nil")
+
+	v.Store(42)
+	assert.Equal(t, 42, v.Load())
+
+	v.Store(84)
+	assert.Equal(t, 84, v.Load())
+
+	assert.Panics(t, func() { v.Store("foo") })
+}
diff --git a/vendor/go.uber.org/atomic/example_test.go b/vendor/go.uber.org/atomic/example_test.go
new file mode 100644
index 0000000..806e11c
--- /dev/null
+++ b/vendor/go.uber.org/atomic/example_test.go
@@ -0,0 +1,43 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package atomic_test
+
+import (
+	"fmt"
+
+	"go.uber.org/atomic"
+)
+
+func Example() {
+	// Uint32 is a thin wrapper around the primitive uint32 type.
+	var atom atomic.Uint32
+
+	// The wrapper ensures that all operations are atomic.
+	atom.Store(42)
+	fmt.Println(atom.Inc())
+	fmt.Println(atom.CAS(43, 0))
+	fmt.Println(atom.Load())
+
+	// Output:
+	// 43
+	// true
+	// 0
+}
diff --git a/vendor/go.uber.org/atomic/glide.lock b/vendor/go.uber.org/atomic/glide.lock
new file mode 100644
index 0000000..3c72c59
--- /dev/null
+++ b/vendor/go.uber.org/atomic/glide.lock
@@ -0,0 +1,17 @@
+hash: f14d51408e3e0e4f73b34e4039484c78059cd7fc5f4996fdd73db20dc8d24f53
+updated: 2016-10-27T00:10:51.16960137-07:00
+imports: []
+testImports:
+- name: github.com/davecgh/go-spew
+  version: 5215b55f46b2b919f50a1df0eaa5886afe4e3b3d
+  subpackages:
+  - spew
+- name: github.com/pmezard/go-difflib
+  version: d8ed2627bdf02c080bf22230dbb337003b7aba2d
+  subpackages:
+  - difflib
+- name: github.com/stretchr/testify
+  version: d77da356e56a7428ad25149ca77381849a6a5232
+  subpackages:
+  - assert
+  - require
diff --git a/vendor/go.uber.org/atomic/glide.yaml b/vendor/go.uber.org/atomic/glide.yaml
new file mode 100644
index 0000000..4cf608e
--- /dev/null
+++ b/vendor/go.uber.org/atomic/glide.yaml
@@ -0,0 +1,6 @@
+package: go.uber.org/atomic
+testImport:
+- package: github.com/stretchr/testify
+  subpackages:
+  - assert
+  - require
diff --git a/vendor/go.uber.org/atomic/scripts/cover.sh b/vendor/go.uber.org/atomic/scripts/cover.sh
new file mode 100755
index 0000000..5dfb65e
--- /dev/null
+++ b/vendor/go.uber.org/atomic/scripts/cover.sh
@@ -0,0 +1,40 @@
+#!/bin/bash
+
+set -e
+
+COVER=cover
+ROOT_PKG=go.uber.org/atomic
+
+if [[ -d "$COVER" ]]; then
+	rm -rf "$COVER"
+fi
+mkdir -p "$COVER"
+
+i=0
+for pkg in "$@"; do
+	i=$((i + 1))
+
+	extracoverpkg=""
+	if [[ -f "$GOPATH/src/$pkg/.extra-coverpkg" ]]; then
+		extracoverpkg=$( \
+			sed -e "s|^|$pkg/|g" < "$GOPATH/src/$pkg/.extra-coverpkg" \
+			| tr '\n' ',')
+	fi
+
+	coverpkg=$(go list -json "$pkg" | jq -r '
+		.Deps
+		| map(select(startswith("'"$ROOT_PKG"'")))
+		| map(select(contains("/vendor/") | not))
+		| . + ["'"$pkg"'"]
+		| join(",")
+	')
+	if [[ -n "$extracoverpkg" ]]; then
+		coverpkg="$extracoverpkg$coverpkg"
+	fi
+
+	go test \
+		-coverprofile "$COVER/cover.${i}.out" -coverpkg "$coverpkg" \
+		-v "$pkg"
+done
+
+gocovmerge "$COVER"/*.out > cover.out
diff --git a/vendor/go.uber.org/atomic/scripts/test-ubergo.sh b/vendor/go.uber.org/atomic/scripts/test-ubergo.sh
new file mode 100755
index 0000000..9bc526d
--- /dev/null
+++ b/vendor/go.uber.org/atomic/scripts/test-ubergo.sh
@@ -0,0 +1,26 @@
+#!/bin/bash
+set -euox pipefail
+IFS=$'\n\t'
+
+# This script creates a fake GOPATH, symlinks in the current
+# directory as uber-go/atomic and verifies that tests still pass.
+
+WORK_DIR=`mktemp -d`
+function cleanup {
+	rm -rf "$WORK_DIR"
+}
+trap cleanup EXIT
+
+
+export GOPATH="$WORK_DIR"
+PKG_PARENT="$WORK_DIR/src/github.com/uber-go"
+PKG_DIR="$PKG_PARENT/atomic"
+
+mkdir -p "$PKG_PARENT"
+cp -R `pwd` "$PKG_DIR"
+cd "$PKG_DIR"
+
+# The example imports go.uber.org, fix the import.
+sed -e 's/go.uber.org\/atomic/github.com\/uber-go\/atomic/' -i="" example_test.go
+
+make test
diff --git a/vendor/go.uber.org/atomic/stress_test.go b/vendor/go.uber.org/atomic/stress_test.go
new file mode 100644
index 0000000..4cf1e16
--- /dev/null
+++ b/vendor/go.uber.org/atomic/stress_test.go
@@ -0,0 +1,140 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package atomic
+
+import (
+	"runtime"
+	"sync"
+	"testing"
+)
+
+const (
+	_parallelism = 4
+	_iterations  = 1000
+)
+
+func runStress(f func()) {
+	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(_parallelism))
+
+	var wg sync.WaitGroup
+	wg.Add(_parallelism)
+	for i := 0; i < _parallelism; i++ {
+		go func() {
+			defer wg.Done()
+			for j := 0; j < _iterations; j++ {
+				f()
+			}
+		}()
+	}
+
+	wg.Wait()
+}
+
+func TestStressInt32(t *testing.T) {
+	var atom Int32
+	runStress(func() {
+		atom.Load()
+		atom.Add(1)
+		atom.Sub(2)
+		atom.Inc()
+		atom.Dec()
+		atom.CAS(1, 0)
+		atom.Swap(5)
+		atom.Store(1)
+	})
+}
+
+func TestStressInt64(t *testing.T) {
+	var atom Int64
+	runStress(func() {
+		atom.Load()
+		atom.Add(1)
+		atom.Sub(2)
+		atom.Inc()
+		atom.Dec()
+		atom.CAS(1, 0)
+		atom.Swap(5)
+		atom.Store(1)
+
+	})
+}
+
+func TestStressUint32(t *testing.T) {
+	var atom Uint32
+	runStress(func() {
+		atom.Load()
+		atom.Add(1)
+		atom.Sub(2)
+		atom.Inc()
+		atom.Dec()
+		atom.CAS(1, 0)
+		atom.Swap(5)
+		atom.Store(1)
+	})
+}
+
+func TestStressUint64(t *testing.T) {
+	var atom Uint64
+	runStress(func() {
+		atom.Load()
+		atom.Add(1)
+		atom.Sub(2)
+		atom.Inc()
+		atom.Dec()
+		atom.CAS(1, 0)
+		atom.Swap(5)
+		atom.Store(1)
+	})
+}
+
+func TestStressFloat64(t *testing.T) {
+	var atom Float64
+	runStress(func() {
+		atom.Load()
+		atom.CAS(1.0, 0.1)
+		atom.Add(1.1)
+		atom.Sub(0.2)
+		atom.Store(1.0)
+	})
+}
+
+func TestStressBool(t *testing.T) {
+	var atom Bool
+	runStress(func() {
+		atom.Load()
+		atom.Store(false)
+		atom.Swap(true)
+		atom.Load()
+		atom.Toggle()
+		atom.Toggle()
+	})
+}
+
+func TestStressString(t *testing.T) {
+	var atom String
+	runStress(func() {
+		atom.Load()
+		atom.Store("abc")
+		atom.Load()
+		atom.Store("def")
+
+	})
+}
diff --git a/vendor/go.uber.org/atomic/string.go b/vendor/go.uber.org/atomic/string.go
new file mode 100644
index 0000000..acf0f5b
--- /dev/null
+++ b/vendor/go.uber.org/atomic/string.go
@@ -0,0 +1,51 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package atomic
+
+import "sync/atomic"
+
+// String is an atomic type-safe wrapper around atomic.Value for strings.
+type String struct{ v atomic.Value }
+
+// NewString creates a String.
+func NewString(str string) *String {
+	s := &String{}
+	if str != "" {
+		s.Store(str)
+	}
+	return s
+}
+
+// Load atomically loads the wrapped string.
+func (s *String) Load() string {
+	v := s.v.Load()
+	if v == nil {
+		return ""
+	}
+	return v.(string)
+}
+
+// Store atomically stores the passed string.
+// Note: Converting the string to an interface{} to store in the atomic.Value
+// requires an allocation.
+func (s *String) Store(str string) {
+	s.v.Store(str)
+}
diff --git a/vendor/go.uber.org/atomic/string_test.go b/vendor/go.uber.org/atomic/string_test.go
new file mode 100644
index 0000000..91b793e
--- /dev/null
+++ b/vendor/go.uber.org/atomic/string_test.go
@@ -0,0 +1,43 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package atomic
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestStringNoInitialValue(t *testing.T) {
+	atom := &String{}
+	require.Equal(t, "", atom.Load(), "Initial value should be blank string")
+}
+
+func TestString(t *testing.T) {
+	atom := NewString("")
+	require.Equal(t, "", atom.Load(), "Expected Load to return initialized value")
+
+	atom.Store("abc")
+	require.Equal(t, "abc", atom.Load(), "Unexpected value after Store")
+
+	atom = NewString("bcd")
+	require.Equal(t, "bcd", atom.Load(), "Expected Load to return initialized value")
+}
diff --git a/vendor/go.uber.org/multierr/.codecov.yml b/vendor/go.uber.org/multierr/.codecov.yml
new file mode 100644
index 0000000..6d4d1be
--- /dev/null
+++ b/vendor/go.uber.org/multierr/.codecov.yml
@@ -0,0 +1,15 @@
+coverage:
+  range: 80..100
+  round: down
+  precision: 2
+
+  status:
+    project:                   # measuring the overall project coverage
+      default:                 # context, you can create multiple ones with custom titles
+        enabled: yes           # must be yes|true to enable this status
+        target: 100            # specify the target coverage for each commit status
+                               #   option: "auto" (must increase from parent commit or pull request base)
+                               #   option: "X%" a static target percentage to hit
+        if_not_found: success  # if parent is not found report status as success, error, or failure
+        if_ci_failed: error    # if ci fails report status as success, error, or failure
+
diff --git a/vendor/go.uber.org/multierr/.gitignore b/vendor/go.uber.org/multierr/.gitignore
new file mode 100644
index 0000000..61ead86
--- /dev/null
+++ b/vendor/go.uber.org/multierr/.gitignore
@@ -0,0 +1 @@
+/vendor
diff --git a/vendor/go.uber.org/multierr/.travis.yml b/vendor/go.uber.org/multierr/.travis.yml
new file mode 100644
index 0000000..5ffa8fe
--- /dev/null
+++ b/vendor/go.uber.org/multierr/.travis.yml
@@ -0,0 +1,33 @@
+sudo: false
+language: go
+go_import_path: go.uber.org/multierr
+
+env:
+  global:
+    - GO15VENDOREXPERIMENT=1
+
+go:
+  - 1.7
+  - 1.8
+  - tip
+
+cache:
+  directories:
+    - vendor
+
+before_install:
+- go version
+
+install:
+- |
+  set -e
+  make install_ci
+
+script:
+- |
+  set -e
+  make lint
+  make test_ci
+
+after_success:
+- bash <(curl -s https://codecov.io/bash)
diff --git a/vendor/go.uber.org/multierr/CHANGELOG.md b/vendor/go.uber.org/multierr/CHANGELOG.md
new file mode 100644
index 0000000..898445d
--- /dev/null
+++ b/vendor/go.uber.org/multierr/CHANGELOG.md
@@ -0,0 +1,28 @@
+Releases
+========
+
+v1.1.0 (2017-06-30)
+===================
+
+-   Added an `Errors(error) []error` function to extract the underlying list of
+    errors for a multierr error.
+
+
+v1.0.0 (2017-05-31)
+===================
+
+No changes since v0.2.0. This release is committing to making no breaking
+changes to the current API in the 1.X series.
+
+
+v0.2.0 (2017-04-11)
+===================
+
+-   Repeatedly appending to the same error is now faster due to fewer
+    allocations.
+
+
+v0.1.0 (2017-31-03)
+===================
+
+-   Initial release
diff --git a/vendor/go.uber.org/multierr/LICENSE.txt b/vendor/go.uber.org/multierr/LICENSE.txt
new file mode 100644
index 0000000..858e024
--- /dev/null
+++ b/vendor/go.uber.org/multierr/LICENSE.txt
@@ -0,0 +1,19 @@
+Copyright (c) 2017 Uber Technologies, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/vendor/go.uber.org/multierr/Makefile b/vendor/go.uber.org/multierr/Makefile
new file mode 100644
index 0000000..a7437d0
--- /dev/null
+++ b/vendor/go.uber.org/multierr/Makefile
@@ -0,0 +1,74 @@
+export GO15VENDOREXPERIMENT=1
+
+PACKAGES := $(shell glide nv)
+
+GO_FILES := $(shell \
+	find . '(' -path '*/.*' -o -path './vendor' ')' -prune \
+	-o -name '*.go' -print | cut -b3-)
+
+.PHONY: install
+install:
+	glide --version || go get github.com/Masterminds/glide
+	glide install
+
+.PHONY: build
+build:
+	go build -i $(PACKAGES)
+
+.PHONY: test
+test:
+	go test -cover -race $(PACKAGES)
+
+.PHONY: gofmt
+gofmt:
+	$(eval FMT_LOG := $(shell mktemp -t gofmt.XXXXX))
+	@gofmt -e -s -l $(GO_FILES) > $(FMT_LOG) || true
+	@[ ! -s "$(FMT_LOG)" ] || (echo "gofmt failed:" | cat - $(FMT_LOG) && false)
+
+.PHONY: govet
+govet:
+	$(eval VET_LOG := $(shell mktemp -t govet.XXXXX))
+	@go vet $(PACKAGES) 2>&1 \
+		| grep -v '^exit status' > $(VET_LOG) || true
+	@[ ! -s "$(VET_LOG)" ] || (echo "govet failed:" | cat - $(VET_LOG) && false)
+
+.PHONY: golint
+golint:
+	@go get github.com/golang/lint/golint
+	$(eval LINT_LOG := $(shell mktemp -t golint.XXXXX))
+	@cat /dev/null > $(LINT_LOG)
+	@$(foreach pkg, $(PACKAGES), golint $(pkg) >> $(LINT_LOG) || true;)
+	@[ ! -s "$(LINT_LOG)" ] || (echo "golint failed:" | cat - $(LINT_LOG) && false)
+
+.PHONY: staticcheck
+staticcheck:
+	@go get honnef.co/go/tools/cmd/staticcheck
+	$(eval STATICCHECK_LOG := $(shell mktemp -t staticcheck.XXXXX))
+	@staticcheck $(PACKAGES) 2>&1 > $(STATICCHECK_LOG) || true
+	@[ ! -s "$(STATICCHECK_LOG)" ] || (echo "staticcheck failed:" | cat - $(STATICCHECK_LOG) && false)
+
+.PHONY: lint
+lint: gofmt govet golint staticcheck
+
+.PHONY: cover
+cover:
+	./scripts/cover.sh $(shell go list $(PACKAGES))
+	go tool cover -html=cover.out -o cover.html
+
+update-license:
+	@go get go.uber.org/tools/update-license
+	@update-license \
+		$(shell go list -json $(PACKAGES) | \
+			jq -r '.Dir + "/" + (.GoFiles | .[])')
+
+##############################################################################
+
+.PHONY: install_ci
+install_ci: install
+	go get github.com/wadey/gocovmerge
+	go get github.com/mattn/goveralls
+	go get golang.org/x/tools/cmd/cover
+
+.PHONY: test_ci
+test_ci: install_ci
+	./scripts/cover.sh $(shell go list $(PACKAGES))
diff --git a/vendor/go.uber.org/multierr/README.md b/vendor/go.uber.org/multierr/README.md
new file mode 100644
index 0000000..065088f
--- /dev/null
+++ b/vendor/go.uber.org/multierr/README.md
@@ -0,0 +1,23 @@
+# multierr [![GoDoc][doc-img]][doc] [![Build Status][ci-img]][ci] [![Coverage Status][cov-img]][cov]
+
+`multierr` allows combining one or more Go `error`s together.
+
+## Installation
+
+    go get -u go.uber.org/multierr
+
+## Status
+
+Stable: No breaking changes will be made before 2.0.
+
+-------------------------------------------------------------------------------
+
+Released under the [MIT License].
+
+[MIT License]: LICENSE.txt
+[doc-img]: https://godoc.org/go.uber.org/multierr?status.svg
+[doc]: https://godoc.org/go.uber.org/multierr
+[ci-img]: https://travis-ci.org/uber-go/multierr.svg?branch=master
+[cov-img]: https://codecov.io/gh/uber-go/multierr/branch/master/graph/badge.svg
+[ci]: https://travis-ci.org/uber-go/multierr
+[cov]: https://codecov.io/gh/uber-go/multierr
diff --git a/vendor/go.uber.org/multierr/benchmarks_test.go b/vendor/go.uber.org/multierr/benchmarks_test.go
new file mode 100644
index 0000000..797f5a0
--- /dev/null
+++ b/vendor/go.uber.org/multierr/benchmarks_test.go
@@ -0,0 +1,62 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package multierr
+
+import (
+	"errors"
+	"fmt"
+	"testing"
+)
+
+func BenchmarkAppend(b *testing.B) {
+	errorTypes := []struct {
+		name string
+		err  error
+	}{
+		{
+			name: "nil",
+			err:  nil,
+		},
+		{
+			name: "single error",
+			err:  errors.New("test"),
+		},
+		{
+			name: "multiple errors",
+			err:  appendN(nil, errors.New("err"), 10),
+		},
+	}
+
+	for _, initial := range errorTypes {
+		for _, v := range errorTypes {
+			msg := fmt.Sprintf("append %v to %v", v.name, initial.name)
+			b.Run(msg, func(b *testing.B) {
+				for _, appends := range []int{1, 2, 10} {
+					b.Run(fmt.Sprint(appends), func(b *testing.B) {
+						for i := 0; i < b.N; i++ {
+							appendN(initial.err, v.err, appends)
+						}
+					})
+				}
+			})
+		}
+	}
+}
diff --git a/vendor/go.uber.org/multierr/error.go b/vendor/go.uber.org/multierr/error.go
new file mode 100644
index 0000000..de6ce47
--- /dev/null
+++ b/vendor/go.uber.org/multierr/error.go
@@ -0,0 +1,401 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Package multierr allows combining one or more errors together.
+//
+// Overview
+//
+// Errors can be combined with the use of the Combine function.
+//
+// 	multierr.Combine(
+// 		reader.Close(),
+// 		writer.Close(),
+// 		conn.Close(),
+// 	)
+//
+// If only two errors are being combined, the Append function may be used
+// instead.
+//
+// 	err = multierr.Combine(reader.Close(), writer.Close())
+//
+// This makes it possible to record resource cleanup failures from deferred
+// blocks with the help of named return values.
+//
+// 	func sendRequest(req Request) (err error) {
+// 		conn, err := openConnection()
+// 		if err != nil {
+// 			return err
+// 		}
+// 		defer func() {
+// 			err = multierr.Append(err, conn.Close())
+// 		}()
+// 		// ...
+// 	}
+//
+// The underlying list of errors for a returned error object may be retrieved
+// with the Errors function.
+//
+// 	errors := multierr.Errors(err)
+// 	if len(errors) > 0 {
+// 		fmt.Println("The following errors occurred:")
+// 	}
+//
+// Advanced Usage
+//
+// Errors returned by Combine and Append MAY implement the following
+// interface.
+//
+// 	type errorGroup interface {
+// 		// Returns a slice containing the underlying list of errors.
+// 		//
+// 		// This slice MUST NOT be modified by the caller.
+// 		Errors() []error
+// 	}
+//
+// Note that if you need access to list of errors behind a multierr error, you
+// should prefer using the Errors function. That said, if you need cheap
+// read-only access to the underlying errors slice, you can attempt to cast
+// the error to this interface. You MUST handle the failure case gracefully
+// because errors returned by Combine and Append are not guaranteed to
+// implement this interface.
+//
+// 	var errors []error
+// 	group, ok := err.(errorGroup)
+// 	if ok {
+// 		errors = group.Errors()
+// 	} else {
+// 		errors = []error{err}
+// 	}
+package multierr // import "go.uber.org/multierr"
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"strings"
+	"sync"
+
+	"go.uber.org/atomic"
+)
+
+var (
+	// Separator for single-line error messages.
+	_singlelineSeparator = []byte("; ")
+
+	_newline = []byte("\n")
+
+	// Prefix for multi-line messages
+	_multilinePrefix = []byte("the following errors occurred:")
+
+	// Prefix for the first and following lines of an item in a list of
+	// multi-line error messages.
+	//
+	// For example, if a single item is:
+	//
+	// 	foo
+	// 	bar
+	//
+	// It will become,
+	//
+	// 	 -  foo
+	// 	    bar
+	_multilineSeparator = []byte("\n -  ")
+	_multilineIndent    = []byte("    ")
+)
+
+// _bufferPool is a pool of bytes.Buffers.
+var _bufferPool = sync.Pool{
+	New: func() interface{} {
+		return &bytes.Buffer{}
+	},
+}
+
+type errorGroup interface {
+	Errors() []error
+}
+
+// Errors returns a slice containing zero or more errors that the supplied
+// error is composed of. If the error is nil, the returned slice is empty.
+//
+// 	err := multierr.Append(r.Close(), w.Close())
+// 	errors := multierr.Errors(err)
+//
+// If the error is not composed of other errors, the returned slice contains
+// just the error that was passed in.
+//
+// Callers of this function are free to modify the returned slice.
+func Errors(err error) []error {
+	if err == nil {
+		return nil
+	}
+
+	// Note that we're casting to multiError, not errorGroup. Our contract is
+	// that returned errors MAY implement errorGroup. Errors, however, only
+	// has special behavior for multierr-specific error objects.
+	//
+	// This behavior can be expanded in the future but I think it's prudent to
+	// start with as little as possible in terms of contract and possibility
+	// of misuse.
+	eg, ok := err.(*multiError)
+	if !ok {
+		return []error{err}
+	}
+
+	errors := eg.Errors()
+	result := make([]error, len(errors))
+	copy(result, errors)
+	return result
+}
+
+// multiError is an error that holds one or more errors.
+//
+// An instance of this is guaranteed to be non-empty and flattened. That is,
+// none of the errors inside multiError are other multiErrors.
+//
+// multiError formats to a semi-colon delimited list of error messages with
+// %v and with a more readable multi-line format with %+v.
+type multiError struct {
+	copyNeeded atomic.Bool
+	errors     []error
+}
+
+var _ errorGroup = (*multiError)(nil)
+
+// Errors returns the list of underlying errors.
+//
+// This slice MUST NOT be modified.
+func (merr *multiError) Errors() []error {
+	if merr == nil {
+		return nil
+	}
+	return merr.errors
+}
+
+func (merr *multiError) Error() string {
+	if merr == nil {
+		return ""
+	}
+
+	buff := _bufferPool.Get().(*bytes.Buffer)
+	buff.Reset()
+
+	merr.writeSingleline(buff)
+
+	result := buff.String()
+	_bufferPool.Put(buff)
+	return result
+}
+
+func (merr *multiError) Format(f fmt.State, c rune) {
+	if c == 'v' && f.Flag('+') {
+		merr.writeMultiline(f)
+	} else {
+		merr.writeSingleline(f)
+	}
+}
+
+func (merr *multiError) writeSingleline(w io.Writer) {
+	first := true
+	for _, item := range merr.errors {
+		if first {
+			first = false
+		} else {
+			w.Write(_singlelineSeparator)
+		}
+		io.WriteString(w, item.Error())
+	}
+}
+
+func (merr *multiError) writeMultiline(w io.Writer) {
+	w.Write(_multilinePrefix)
+	for _, item := range merr.errors {
+		w.Write(_multilineSeparator)
+		writePrefixLine(w, _multilineIndent, fmt.Sprintf("%+v", item))
+	}
+}
+
+// Writes s to the writer with the given prefix added before each line after
+// the first.
+func writePrefixLine(w io.Writer, prefix []byte, s string) {
+	first := true
+	for len(s) > 0 {
+		if first {
+			first = false
+		} else {
+			w.Write(prefix)
+		}
+
+		idx := strings.IndexByte(s, '\n')
+		if idx < 0 {
+			idx = len(s) - 1
+		}
+
+		io.WriteString(w, s[:idx+1])
+		s = s[idx+1:]
+	}
+}
+
+type inspectResult struct {
+	// Number of top-level non-nil errors
+	Count int
+
+	// Total number of errors including multiErrors
+	Capacity int
+
+	// Index of the first non-nil error in the list. Value is meaningless if
+	// Count is zero.
+	FirstErrorIdx int
+
+	// Whether the list contains at least one multiError
+	ContainsMultiError bool
+}
+
+// Inspects the given slice of errors so that we can efficiently allocate
+// space for it.
+func inspect(errors []error) (res inspectResult) {
+	first := true
+	for i, err := range errors {
+		if err == nil {
+			continue
+		}
+
+		res.Count++
+		if first {
+			first = false
+			res.FirstErrorIdx = i
+		}
+
+		if merr, ok := err.(*multiError); ok {
+			res.Capacity += len(merr.errors)
+			res.ContainsMultiError = true
+		} else {
+			res.Capacity++
+		}
+	}
+	return
+}
+
+// fromSlice converts the given list of errors into a single error.
+func fromSlice(errors []error) error {
+	res := inspect(errors)
+	switch res.Count {
+	case 0:
+		return nil
+	case 1:
+		// only one non-nil entry
+		return errors[res.FirstErrorIdx]
+	case len(errors):
+		if !res.ContainsMultiError {
+			// already flat
+			return &multiError{errors: errors}
+		}
+	}
+
+	nonNilErrs := make([]error, 0, res.Capacity)
+	for _, err := range errors[res.FirstErrorIdx:] {
+		if err == nil {
+			continue
+		}
+
+		if nested, ok := err.(*multiError); ok {
+			nonNilErrs = append(nonNilErrs, nested.errors...)
+		} else {
+			nonNilErrs = append(nonNilErrs, err)
+		}
+	}
+
+	return &multiError{errors: nonNilErrs}
+}
+
+// Combine combines the passed errors into a single error.
+//
+// If zero arguments were passed or if all items are nil, a nil error is
+// returned.
+//
+// 	Combine(nil, nil)  // == nil
+//
+// If only a single error was passed, it is returned as-is.
+//
+// 	Combine(err)  // == err
+//
+// Combine skips over nil arguments so this function may be used to combine
+// together errors from operations that fail independently of each other.
+//
+// 	multierr.Combine(
+// 		reader.Close(),
+// 		writer.Close(),
+// 		pipe.Close(),
+// 	)
+//
+// If any of the passed errors is a multierr error, it will be flattened along
+// with the other errors.
+//
+// 	multierr.Combine(multierr.Combine(err1, err2), err3)
+// 	// is the same as
+// 	multierr.Combine(err1, err2, err3)
+//
+// The returned error formats into a readable multi-line error message if
+// formatted with %+v.
+//
+// 	fmt.Sprintf("%+v", multierr.Combine(err1, err2))
+func Combine(errors ...error) error {
+	return fromSlice(errors)
+}
+
+// Append appends the given errors together. Either value may be nil.
+//
+// This function is a specialization of Combine for the common case where
+// there are only two errors.
+//
+// 	err = multierr.Append(reader.Close(), writer.Close())
+//
+// The following pattern may also be used to record failure of deferred
+// operations without losing information about the original error.
+//
+// 	func doSomething(..) (err error) {
+// 		f := acquireResource()
+// 		defer func() {
+// 			err = multierr.Append(err, f.Close())
+// 		}()
+func Append(left error, right error) error {
+	switch {
+	case left == nil:
+		return right
+	case right == nil:
+		return left
+	}
+
+	if _, ok := right.(*multiError); !ok {
+		if l, ok := left.(*multiError); ok && !l.copyNeeded.Swap(true) {
+			// Common case where the error on the left is constantly being
+			// appended to.
+			errs := append(l.errors, right)
+			return &multiError{errors: errs}
+		} else if !ok {
+			// Both errors are single errors.
+			return &multiError{errors: []error{left, right}}
+		}
+	}
+
+	// Either right or both, left and right, are multiErrors. Rely on usual
+	// expensive logic.
+	errors := [2]error{left, right}
+	return fromSlice(errors[0:])
+}
diff --git a/vendor/go.uber.org/multierr/error_test.go b/vendor/go.uber.org/multierr/error_test.go
new file mode 100644
index 0000000..9384ff5
--- /dev/null
+++ b/vendor/go.uber.org/multierr/error_test.go
@@ -0,0 +1,511 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package multierr
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// richFormatError is an error that prints a different output depending on
+// whether %v or %+v was used.
+type richFormatError struct{}
+
+func (r richFormatError) Error() string {
+	return fmt.Sprint(r)
+}
+
+func (richFormatError) Format(f fmt.State, c rune) {
+	if c == 'v' && f.Flag('+') {
+		io.WriteString(f, "multiline\nmessage\nwith plus")
+	} else {
+		io.WriteString(f, "without plus")
+	}
+}
+
+func appendN(initial, err error, n int) error {
+	errs := initial
+	for i := 0; i < n; i++ {
+		errs = Append(errs, err)
+	}
+	return errs
+}
+
+func newMultiErr(errors ...error) error {
+	return &multiError{errors: errors}
+}
+
+func TestCombine(t *testing.T) {
+	tests := []struct {
+		// Input
+		giveErrors []error
+
+		// Resulting error
+		wantError error
+
+		// %+v and %v string representations
+		wantMultiline  string
+		wantSingleline string
+	}{
+		{
+			giveErrors: nil,
+			wantError:  nil,
+		},
+		{
+			giveErrors: []error{},
+			wantError:  nil,
+		},
+		{
+			giveErrors: []error{
+				errors.New("foo"),
+				nil,
+				newMultiErr(
+					errors.New("bar"),
+				),
+				nil,
+			},
+			wantError: newMultiErr(
+				errors.New("foo"),
+				errors.New("bar"),
+			),
+			wantMultiline: "the following errors occurred:\n" +
+				" -  foo\n" +
+				" -  bar",
+			wantSingleline: "foo; bar",
+		},
+		{
+			giveErrors: []error{
+				errors.New("foo"),
+				newMultiErr(
+					errors.New("bar"),
+				),
+			},
+			wantError: newMultiErr(
+				errors.New("foo"),
+				errors.New("bar"),
+			),
+			wantMultiline: "the following errors occurred:\n" +
+				" -  foo\n" +
+				" -  bar",
+			wantSingleline: "foo; bar",
+		},
+		{
+			giveErrors:     []error{errors.New("great sadness")},
+			wantError:      errors.New("great sadness"),
+			wantMultiline:  "great sadness",
+			wantSingleline: "great sadness",
+		},
+		{
+			giveErrors: []error{
+				errors.New("foo"),
+				errors.New("bar"),
+			},
+			wantError: newMultiErr(
+				errors.New("foo"),
+				errors.New("bar"),
+			),
+			wantMultiline: "the following errors occurred:\n" +
+				" -  foo\n" +
+				" -  bar",
+			wantSingleline: "foo; bar",
+		},
+		{
+			giveErrors: []error{
+				errors.New("great sadness"),
+				errors.New("multi\n  line\nerror message"),
+				errors.New("single line error message"),
+			},
+			wantError: newMultiErr(
+				errors.New("great sadness"),
+				errors.New("multi\n  line\nerror message"),
+				errors.New("single line error message"),
+			),
+			wantMultiline: "the following errors occurred:\n" +
+				" -  great sadness\n" +
+				" -  multi\n" +
+				"      line\n" +
+				"    error message\n" +
+				" -  single line error message",
+			wantSingleline: "great sadness; " +
+				"multi\n  line\nerror message; " +
+				"single line error message",
+		},
+		{
+			giveErrors: []error{
+				errors.New("foo"),
+				newMultiErr(
+					errors.New("bar"),
+					errors.New("baz"),
+				),
+				errors.New("qux"),
+			},
+			wantError: newMultiErr(
+				errors.New("foo"),
+				errors.New("bar"),
+				errors.New("baz"),
+				errors.New("qux"),
+			),
+			wantMultiline: "the following errors occurred:\n" +
+				" -  foo\n" +
+				" -  bar\n" +
+				" -  baz\n" +
+				" -  qux",
+			wantSingleline: "foo; bar; baz; qux",
+		},
+		{
+			giveErrors: []error{
+				errors.New("foo"),
+				nil,
+				newMultiErr(
+					errors.New("bar"),
+				),
+				nil,
+			},
+			wantError: newMultiErr(
+				errors.New("foo"),
+				errors.New("bar"),
+			),
+			wantMultiline: "the following errors occurred:\n" +
+				" -  foo\n" +
+				" -  bar",
+			wantSingleline: "foo; bar",
+		},
+		{
+			giveErrors: []error{
+				errors.New("foo"),
+				newMultiErr(
+					errors.New("bar"),
+				),
+			},
+			wantError: newMultiErr(
+				errors.New("foo"),
+				errors.New("bar"),
+			),
+			wantMultiline: "the following errors occurred:\n" +
+				" -  foo\n" +
+				" -  bar",
+			wantSingleline: "foo; bar",
+		},
+		{
+			giveErrors: []error{
+				errors.New("foo"),
+				richFormatError{},
+				errors.New("bar"),
+			},
+			wantError: newMultiErr(
+				errors.New("foo"),
+				richFormatError{},
+				errors.New("bar"),
+			),
+			wantMultiline: "the following errors occurred:\n" +
+				" -  foo\n" +
+				" -  multiline\n" +
+				"    message\n" +
+				"    with plus\n" +
+				" -  bar",
+			wantSingleline: "foo; without plus; bar",
+		},
+	}
+
+	for i, tt := range tests {
+		t.Run(fmt.Sprint(i), func(t *testing.T) {
+			err := Combine(tt.giveErrors...)
+			require.Equal(t, tt.wantError, err)
+
+			if tt.wantMultiline != "" {
+				t.Run("Sprintf/multiline", func(t *testing.T) {
+					assert.Equal(t, tt.wantMultiline, fmt.Sprintf("%+v", err))
+				})
+			}
+
+			if tt.wantSingleline != "" {
+				t.Run("Sprintf/singleline", func(t *testing.T) {
+					assert.Equal(t, tt.wantSingleline, fmt.Sprintf("%v", err))
+				})
+
+				t.Run("Error()", func(t *testing.T) {
+					assert.Equal(t, tt.wantSingleline, err.Error())
+				})
+
+				if s, ok := err.(fmt.Stringer); ok {
+					t.Run("String()", func(t *testing.T) {
+						assert.Equal(t, tt.wantSingleline, s.String())
+					})
+				}
+			}
+		})
+	}
+}
+
+func TestCombineDoesNotModifySlice(t *testing.T) {
+	errors := []error{
+		errors.New("foo"),
+		nil,
+		errors.New("bar"),
+	}
+
+	assert.NotNil(t, Combine(errors...))
+	assert.Len(t, errors, 3)
+	assert.Nil(t, errors[1], 3)
+}
+
+func TestAppend(t *testing.T) {
+	tests := []struct {
+		left  error
+		right error
+		want  error
+	}{
+		{
+			left:  nil,
+			right: nil,
+			want:  nil,
+		},
+		{
+			left:  nil,
+			right: errors.New("great sadness"),
+			want:  errors.New("great sadness"),
+		},
+		{
+			left:  errors.New("great sadness"),
+			right: nil,
+			want:  errors.New("great sadness"),
+		},
+		{
+			left:  errors.New("foo"),
+			right: errors.New("bar"),
+			want: newMultiErr(
+				errors.New("foo"),
+				errors.New("bar"),
+			),
+		},
+		{
+			left: newMultiErr(
+				errors.New("foo"),
+				errors.New("bar"),
+			),
+			right: errors.New("baz"),
+			want: newMultiErr(
+				errors.New("foo"),
+				errors.New("bar"),
+				errors.New("baz"),
+			),
+		},
+		{
+			left: errors.New("baz"),
+			right: newMultiErr(
+				errors.New("foo"),
+				errors.New("bar"),
+			),
+			want: newMultiErr(
+				errors.New("baz"),
+				errors.New("foo"),
+				errors.New("bar"),
+			),
+		},
+		{
+			left: newMultiErr(
+				errors.New("foo"),
+			),
+			right: newMultiErr(
+				errors.New("bar"),
+			),
+			want: newMultiErr(
+				errors.New("foo"),
+				errors.New("bar"),
+			),
+		},
+	}
+
+	for _, tt := range tests {
+		assert.Equal(t, tt.want, Append(tt.left, tt.right))
+	}
+}
+
+type notMultiErr struct{}
+
+var _ errorGroup = notMultiErr{}
+
+func (notMultiErr) Error() string {
+	return "great sadness"
+}
+
+func (notMultiErr) Errors() []error {
+	return []error{errors.New("great sadness")}
+}
+
+func TestErrors(t *testing.T) {
+	tests := []struct {
+		give error
+		want []error
+
+		// Don't attempt to cast to errorGroup or *multiError
+		dontCast bool
+	}{
+		{dontCast: true}, // nil
+		{
+			give:     errors.New("hi"),
+			want:     []error{errors.New("hi")},
+			dontCast: true,
+		},
+		{
+			// We don't yet support non-multierr errors.
+			give:     notMultiErr{},
+			want:     []error{notMultiErr{}},
+			dontCast: true,
+		},
+		{
+			give: Combine(
+				errors.New("foo"),
+				errors.New("bar"),
+			),
+			want: []error{
+				errors.New("foo"),
+				errors.New("bar"),
+			},
+		},
+		{
+			give: Append(
+				errors.New("foo"),
+				errors.New("bar"),
+			),
+			want: []error{
+				errors.New("foo"),
+				errors.New("bar"),
+			},
+		},
+		{
+			give: Append(
+				errors.New("foo"),
+				Combine(
+					errors.New("bar"),
+				),
+			),
+			want: []error{
+				errors.New("foo"),
+				errors.New("bar"),
+			},
+		},
+		{
+			give: Combine(
+				errors.New("foo"),
+				Append(
+					errors.New("bar"),
+					errors.New("baz"),
+				),
+				errors.New("qux"),
+			),
+			want: []error{
+				errors.New("foo"),
+				errors.New("bar"),
+				errors.New("baz"),
+				errors.New("qux"),
+			},
+		},
+	}
+
+	for i, tt := range tests {
+		t.Run(fmt.Sprint(i), func(t *testing.T) {
+			t.Run("Errors()", func(t *testing.T) {
+				require.Equal(t, tt.want, Errors(tt.give))
+			})
+
+			if tt.dontCast {
+				return
+			}
+
+			t.Run("multiError", func(t *testing.T) {
+				require.Equal(t, tt.want, tt.give.(*multiError).Errors())
+			})
+
+			t.Run("errorGroup", func(t *testing.T) {
+				require.Equal(t, tt.want, tt.give.(errorGroup).Errors())
+			})
+		})
+	}
+}
+
+func createMultiErrWithCapacity() error {
+	// Create a multiError that has capacity for more errors so Append will
+	// modify the underlying array that may be shared.
+	return appendN(nil, errors.New("append"), 50)
+}
+
+func TestAppendDoesNotModify(t *testing.T) {
+	initial := createMultiErrWithCapacity()
+	err1 := Append(initial, errors.New("err1"))
+	err2 := Append(initial, errors.New("err2"))
+
+	// Make sure the error messages match, since we do modify the copyNeeded
+	// atomic, the values cannot be compared.
+	assert.EqualError(t, initial, createMultiErrWithCapacity().Error(), "Initial should not be modified")
+
+	assert.EqualError(t, err1, Append(createMultiErrWithCapacity(), errors.New("err1")).Error())
+	assert.EqualError(t, err2, Append(createMultiErrWithCapacity(), errors.New("err2")).Error())
+}
+
+func TestAppendRace(t *testing.T) {
+	initial := createMultiErrWithCapacity()
+
+	var wg sync.WaitGroup
+	for i := 0; i < 10; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+
+			err := initial
+			for j := 0; j < 10; j++ {
+				err = Append(err, errors.New("err"))
+			}
+		}()
+	}
+
+	wg.Wait()
+}
+
+func TestErrorsSliceIsImmutable(t *testing.T) {
+	err1 := errors.New("err1")
+	err2 := errors.New("err2")
+
+	err := Append(err1, err2)
+	gotErrors := Errors(err)
+	require.Equal(t, []error{err1, err2}, gotErrors, "errors must match")
+
+	gotErrors[0] = nil
+	gotErrors[1] = errors.New("err3")
+
+	require.Equal(t, []error{err1, err2}, Errors(err),
+		"errors must match after modification")
+}
+
+func TestNilMultierror(t *testing.T) {
+	// For safety, all operations on multiError should be safe even if it is
+	// nil.
+	var err *multiError
+
+	require.Empty(t, err.Error())
+	require.Empty(t, err.Errors())
+}
diff --git a/vendor/go.uber.org/multierr/example_test.go b/vendor/go.uber.org/multierr/example_test.go
new file mode 100644
index 0000000..da4d914
--- /dev/null
+++ b/vendor/go.uber.org/multierr/example_test.go
@@ -0,0 +1,72 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package multierr_test
+
+import (
+	"errors"
+	"fmt"
+
+	"go.uber.org/multierr"
+)
+
+func ExampleCombine() {
+	err := multierr.Combine(
+		errors.New("call 1 failed"),
+		nil, // successful request
+		errors.New("call 3 failed"),
+		nil, // successful request
+		errors.New("call 5 failed"),
+	)
+	fmt.Printf("%+v", err)
+	// Output:
+	// the following errors occurred:
+	//  -  call 1 failed
+	//  -  call 3 failed
+	//  -  call 5 failed
+}
+
+func ExampleAppend() {
+	var err error
+	err = multierr.Append(err, errors.New("call 1 failed"))
+	err = multierr.Append(err, errors.New("call 2 failed"))
+	fmt.Println(err)
+	// Output:
+	// call 1 failed; call 2 failed
+}
+
+func ExampleErrors() {
+	err := multierr.Combine(
+		nil, // successful request
+		errors.New("call 2 failed"),
+		errors.New("call 3 failed"),
+	)
+	err = multierr.Append(err, nil) // successful request
+	err = multierr.Append(err, errors.New("call 5 failed"))
+
+	errors := multierr.Errors(err)
+	for _, err := range errors {
+		fmt.Println(err)
+	}
+	// Output:
+	// call 2 failed
+	// call 3 failed
+	// call 5 failed
+}
diff --git a/vendor/go.uber.org/multierr/glide.lock b/vendor/go.uber.org/multierr/glide.lock
new file mode 100644
index 0000000..f9ea94c
--- /dev/null
+++ b/vendor/go.uber.org/multierr/glide.lock
@@ -0,0 +1,19 @@
+hash: b53b5e9a84b9cb3cc4b2d0499e23da2feca1eec318ce9bb717ecf35bf24bf221
+updated: 2017-04-10T13:34:45.671678062-07:00
+imports:
+- name: go.uber.org/atomic
+  version: 3b8db5e93c4c02efbc313e17b2e796b0914a01fb
+testImports:
+- name: github.com/davecgh/go-spew
+  version: 6d212800a42e8ab5c146b8ace3490ee17e5225f9
+  subpackages:
+  - spew
+- name: github.com/pmezard/go-difflib
+  version: d8ed2627bdf02c080bf22230dbb337003b7aba2d
+  subpackages:
+  - difflib
+- name: github.com/stretchr/testify
+  version: 69483b4bd14f5845b5a1e55bca19e954e827f1d0
+  subpackages:
+  - assert
+  - require
diff --git a/vendor/go.uber.org/multierr/glide.yaml b/vendor/go.uber.org/multierr/glide.yaml
new file mode 100644
index 0000000..6ef084e
--- /dev/null
+++ b/vendor/go.uber.org/multierr/glide.yaml
@@ -0,0 +1,8 @@
+package: go.uber.org/multierr
+import:
+- package: go.uber.org/atomic
+  version: ^1
+testImport:
+- package: github.com/stretchr/testify
+  subpackages:
+  - assert
diff --git a/vendor/go.uber.org/multierr/scripts/cover.sh b/vendor/go.uber.org/multierr/scripts/cover.sh
new file mode 100755
index 0000000..e7f2b88
--- /dev/null
+++ b/vendor/go.uber.org/multierr/scripts/cover.sh
@@ -0,0 +1,40 @@
+#!/bin/bash -e
+
+COVER=cover
+ROOT_PKG=go.uber.org/multierr
+
+if [[ -d "$COVER" ]]; then
+	rm -rf "$COVER"
+fi
+mkdir -p "$COVER"
+
+i=0
+for pkg in "$@"; do
+	i=$((i + 1))
+
+	extracoverpkg=""
+	if [[ -f "$GOPATH/src/$pkg/.extra-coverpkg" ]]; then
+		extracoverpkg=$( \
+			sed -e "s|^|$pkg/|g" < "$GOPATH/src/$pkg/.extra-coverpkg" \
+			| tr '\n' ',')
+	fi
+
+	coverpkg=$(go list -json "$pkg" | jq -r '
+		.Deps
+		| . + ["'"$pkg"'"]
+		| map
+			( select(startswith("'"$ROOT_PKG"'"))
+			| select(contains("/vendor/") | not)
+			)
+		| join(",")
+	')
+	if [[ -n "$extracoverpkg" ]]; then
+		coverpkg="$extracoverpkg$coverpkg"
+	fi
+
+	go test \
+		-coverprofile "$COVER/cover.${i}.out" -coverpkg "$coverpkg" \
+		-v "$pkg"
+done
+
+gocovmerge "$COVER"/*.out > cover.out
diff --git a/vendor/go.uber.org/zap/.codecov.yml b/vendor/go.uber.org/zap/.codecov.yml
new file mode 100644
index 0000000..8e5ca7d
--- /dev/null
+++ b/vendor/go.uber.org/zap/.codecov.yml
@@ -0,0 +1,17 @@
+coverage:
+  range: 80..100
+  round: down
+  precision: 2
+
+  status:
+    project:                   # measuring the overall project coverage
+      default:                 # context, you can create multiple ones with custom titles
+        enabled: yes           # must be yes|true to enable this status
+        target: 95%            # specify the target coverage for each commit status
+                               #   option: "auto" (must increase from parent commit or pull request base)
+                               #   option: "X%" a static target percentage to hit
+        if_not_found: success  # if parent is not found report status as success, error, or failure
+        if_ci_failed: error    # if ci fails report status as success, error, or failure
+ignore:
+  - internal/readme/readme.go
+
diff --git a/vendor/go.uber.org/zap/.gitignore b/vendor/go.uber.org/zap/.gitignore
new file mode 100644
index 0000000..08fbde6
--- /dev/null
+++ b/vendor/go.uber.org/zap/.gitignore
@@ -0,0 +1,28 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+vendor
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test
+*.prof
+*.pprof
+*.out
+*.log
diff --git a/vendor/go.uber.org/zap/.readme.tmpl b/vendor/go.uber.org/zap/.readme.tmpl
new file mode 100644
index 0000000..550dcda
--- /dev/null
+++ b/vendor/go.uber.org/zap/.readme.tmpl
@@ -0,0 +1,108 @@
+# :zap: zap [![GoDoc][doc-img]][doc] [![Build Status][ci-img]][ci] [![Coverage Status][cov-img]][cov]
+
+Blazing fast, structured, leveled logging in Go.
+
+## Installation
+
+`go get -u go.uber.org/zap`
+
+Note that zap only supports the two most recent minor versions of Go.
+
+## Quick Start
+
+In contexts where performance is nice, but not critical, use the
+`SugaredLogger`. It's 4-10x faster than than other structured logging
+packages and includes both structured and `printf`-style APIs.
+
+```go
+logger, _ := zap.NewProduction()
+defer logger.Sync() // flushes buffer, if any
+sugar := logger.Sugar()
+sugar.Infow("failed to fetch URL",
+  // Structured context as loosely typed key-value pairs.
+  "url", url,
+  "attempt", 3,
+  "backoff", time.Second,
+)
+sugar.Infof("Failed to fetch URL: %s", url)
+```
+
+When performance and type safety are critical, use the `Logger`. It's even
+faster than the `SugaredLogger` and allocates far less, but it only supports
+structured logging.
+
+```go
+logger, _ := zap.NewProduction()
+defer logger.Sync()
+logger.Info("failed to fetch URL",
+  // Structured context as strongly typed Field values.
+  zap.String("url", url),
+  zap.Int("attempt", 3),
+  zap.Duration("backoff", time.Second),
+)
+```
+
+See the [documentation][doc] and [FAQ](FAQ.md) for more details.
+
+## Performance
+
+For applications that log in the hot path, reflection-based serialization and
+string formatting are prohibitively expensive &mdash; they're CPU-intensive
+and make many small allocations. Put differently, using `encoding/json` and
+`fmt.Fprintf` to log tons of `interface{}`s makes your application slow.
+
+Zap takes a different approach. It includes a reflection-free, zero-allocation
+JSON encoder, and the base `Logger` strives to avoid serialization overhead
+and allocations wherever possible. By building the high-level `SugaredLogger`
+on that foundation, zap lets users *choose* when they need to count every
+allocation and when they'd prefer a more familiar, loosely typed API.
+
+As measured by its own [benchmarking suite][], not only is zap more performant
+than comparable structured logging packages &mdash; it's also faster than the
+standard library. Like all benchmarks, take these with a grain of salt.<sup
+id="anchor-versions">[1](#footnote-versions)</sup>
+
+Log a message and 10 fields:
+
+{{.BenchmarkAddingFields}}
+
+Log a message with a logger that already has 10 fields of context:
+
+{{.BenchmarkAccumulatedContext}}
+
+Log a static string, without any context or `printf`-style templating:
+
+{{.BenchmarkWithoutFields}}
+
+## Development Status: Stable
+
+All APIs are finalized, and no breaking changes will be made in the 1.x series
+of releases. Users of semver-aware dependency management systems should pin
+zap to `^1`.
+
+## Contributing
+
+We encourage and support an active, healthy community of contributors &mdash;
+including you! Details are in the [contribution guide](CONTRIBUTING.md) and
+the [code of conduct](CODE_OF_CONDUCT.md). The zap maintainers keep an eye on
+issues and pull requests, but you can also report any negative conduct to
+oss-conduct@uber.com. That email list is a private, safe space; even the zap
+maintainers don't have access, so don't hesitate to hold us to a high
+standard.
+
+<hr>
+
+Released under the [MIT License](LICENSE.txt).
+
+<sup id="footnote-versions">1</sup> In particular, keep in mind that we may be
+benchmarking against slightly older versions of other packages. Versions are
+pinned in zap's [glide.lock][] file. [↩](#anchor-versions)
+
+[doc-img]: https://godoc.org/go.uber.org/zap?status.svg
+[doc]: https://godoc.org/go.uber.org/zap
+[ci-img]: https://travis-ci.org/uber-go/zap.svg?branch=master
+[ci]: https://travis-ci.org/uber-go/zap
+[cov-img]: https://codecov.io/gh/uber-go/zap/branch/master/graph/badge.svg
+[cov]: https://codecov.io/gh/uber-go/zap
+[benchmarking suite]: https://github.com/uber-go/zap/tree/master/benchmarks
+[glide.lock]: https://github.com/uber-go/zap/blob/master/glide.lock
diff --git a/vendor/go.uber.org/zap/.travis.yml b/vendor/go.uber.org/zap/.travis.yml
new file mode 100644
index 0000000..fc92e2f
--- /dev/null
+++ b/vendor/go.uber.org/zap/.travis.yml
@@ -0,0 +1,23 @@
+language: go
+sudo: false
+go:
+  - 1.7
+  - 1.8
+  - 1.9
+go_import_path: go.uber.org/zap
+env:
+  global:
+    - GO15VENDOREXPERIMENT=1
+    - TEST_TIMEOUT_SCALE=10
+cache:
+  directories:
+    - vendor
+install:
+  - make dependencies
+script:
+  - make lint
+  - make test
+  - make bench
+after_success:
+  - make cover
+  - bash <(curl -s https://codecov.io/bash)
diff --git a/vendor/go.uber.org/zap/CHANGELOG.md b/vendor/go.uber.org/zap/CHANGELOG.md
new file mode 100644
index 0000000..6a1609a
--- /dev/null
+++ b/vendor/go.uber.org/zap/CHANGELOG.md
@@ -0,0 +1,270 @@
+# Changelog
+
+## v1.7.1 (25 Sep 2017)
+
+Bugfixes:
+* [#504][]: Store strings when using AddByteString with the map encoder.
+
+## v1.7.0 (21 Sep 2017)
+
+Enhancements:
+
+* [#487][]: Add `NewStdLogAt`, which extends `NewStdLog` by allowing the user
+  to specify the level of the logged messages.
+
+## v1.6.0 (30 Aug 2017)
+
+Enhancements:
+
+* [#491][]: Omit zap stack frames from stacktraces.
+* [#490][]: Add a `ContextMap` method to observer logs for simpler
+  field validation in tests.
+
+## v1.5.0 (22 Jul 2017)
+
+Enhancements:
+
+* [#460][] and [#470][]: Support errors produced by `go.uber.org/multierr`.
+* [#465][]: Support user-supplied encoders for logger names.
+
+Bugfixes:
+
+* [#477][]: Fix a bug that incorrectly truncated deep stacktraces.
+
+Thanks to @richard-tunein and @pavius for their contributions to this release.
+
+## v1.4.1 (08 Jun 2017)
+
+This release fixes two bugs.
+
+Bugfixes:
+
+* [#435][]: Support a variety of case conventions when unmarshaling levels.
+* [#444][]: Fix a panic in the observer.
+
+## v1.4.0 (12 May 2017)
+
+This release adds a few small features and is fully backward-compatible.
+
+Enhancements:
+
+* [#424][]: Add a `LineEnding` field to `EncoderConfig`, allowing users to
+  override the Unix-style default.
+* [#425][]: Preserve time zones when logging times.
+* [#431][]: Make `zap.AtomicLevel` implement `fmt.Stringer`, which makes a
+  variety of operations a bit simpler.
+
+## v1.3.0 (25 Apr 2017)
+
+This release adds an enhancement to zap's testing helpers as well as the
+ability to marshal an AtomicLevel. It is fully backward-compatible.
+
+Enhancements:
+
+* [#415][]: Add a substring-filtering helper to zap's observer. This is
+  particularly useful when testing the `SugaredLogger`.
+* [#416][]: Make `AtomicLevel` implement `encoding.TextMarshaler`.
+
+## v1.2.0 (13 Apr 2017)
+
+This release adds a gRPC compatibility wrapper. It is fully backward-compatible.
+
+Enhancements:
+
+* [#402][]: Add a `zapgrpc` package that wraps zap's Logger and implements
+  `grpclog.Logger`.
+
+## v1.1.0 (31 Mar 2017)
+
+This release fixes two bugs and adds some enhancements to zap's testing helpers.
+It is fully backward-compatible.
+
+Bugfixes:
+
+* [#385][]: Fix caller path trimming on Windows.
+* [#396][]: Fix a panic when attempting to use non-existent directories with
+  zap's configuration struct.
+
+Enhancements:
+
+* [#386][]: Add filtering helpers to zaptest's observing logger.
+
+Thanks to @moitias for contributing to this release.
+
+## v1.0.0 (14 Mar 2017)
+
+This is zap's first stable release. All exported APIs are now final, and no
+further breaking changes will be made in the 1.x release series. Anyone using a
+semver-aware dependency manager should now pin to `^1`.
+
+Breaking changes:
+
+* [#366][]: Add byte-oriented APIs to encoders to log UTF-8 encoded text without
+  casting from `[]byte` to `string`.
+* [#364][]: To support buffering outputs, add `Sync` methods to `zapcore.Core`,
+  `zap.Logger`, and `zap.SugaredLogger`.
+* [#371][]: Rename the `testutils` package to `zaptest`, which is less likely to
+  clash with other testing helpers.
+
+Bugfixes:
+
+* [#362][]: Make the ISO8601 time formatters fixed-width, which is friendlier
+  for tab-separated console output.
+* [#369][]: Remove the automatic locks in `zapcore.NewCore`, which allows zap to
+  work with concurrency-safe `WriteSyncer` implementations.
+* [#347][]: Stop reporting errors when trying to `fsync` standard out on Linux
+  systems.
+* [#373][]: Report the correct caller from zap's standard library
+  interoperability wrappers.
+
+Enhancements:
+
+* [#348][]: Add a registry allowing third-party encodings to work with zap's
+  built-in `Config`.
+* [#327][]: Make the representation of logger callers configurable (like times,
+  levels, and durations).
+* [#376][]: Allow third-party encoders to use their own buffer pools, which
+  removes the last performance advantage that zap's encoders have over plugins.
+* [#346][]: Add `CombineWriteSyncers`, a convenience function to tee multiple
+  `WriteSyncer`s and lock the result.
+* [#365][]: Make zap's stacktraces compatible with mid-stack inlining (coming in
+  Go 1.9).
+* [#372][]: Export zap's observing logger as `zaptest/observer`. This makes it
+  easier for particularly punctilious users to unit test their application's
+  logging.
+
+Thanks to @suyash, @htrendev, @flisky, @Ulexus, and @skipor for their
+contributions to this release.
+
+## v1.0.0-rc.3 (7 Mar 2017)
+
+This is the third release candidate for zap's stable release. There are no
+breaking changes.
+
+Bugfixes:
+
+* [#339][]: Byte slices passed to `zap.Any` are now correctly treated as binary blobs
+  rather than `[]uint8`.
+
+Enhancements:
+
+* [#307][]: Users can opt into colored output for log levels.
+* [#353][]: In addition to hijacking the output of the standard library's
+  package-global logging functions, users can now construct a zap-backed
+  `log.Logger` instance.
+* [#311][]: Frames from common runtime functions and some of zap's internal
+  machinery are now omitted from stacktraces.
+
+Thanks to @ansel1 and @suyash for their contributions to this release.
+
+## v1.0.0-rc.2 (21 Feb 2017)
+
+This is the second release candidate for zap's stable release. It includes two
+breaking changes.
+
+Breaking changes:
+
+* [#316][]: Zap's global loggers are now fully concurrency-safe
+  (previously, users had to ensure that `ReplaceGlobals` was called before the
+  loggers were in use). However, they must now be accessed via the `L()` and
+  `S()` functions. Users can update their projects with
+
+  ```
+  gofmt -r "zap.L -> zap.L()" -w .
+  gofmt -r "zap.S -> zap.S()" -w .
+  ```
+* [#309][] and [#317][]: RC1 was mistakenly shipped with invalid
+  JSON and YAML struct tags on all config structs. This release fixes the tags
+  and adds static analysis to prevent similar bugs in the future.
+
+Bugfixes:
+
+* [#321][]: Redirecting the standard library's `log` output now
+  correctly reports the logger's caller.
+
+Enhancements:
+
+* [#325][] and [#333][]: Zap now transparently supports non-standard, rich
+  errors like those produced by `github.com/pkg/errors`.
+* [#326][]: Though `New(nil)` continues to return a no-op logger, `NewNop()` is
+  now preferred. Users can update their projects with `gofmt -r 'zap.New(nil) ->
+  zap.NewNop()' -w .`.
+* [#300][]: Incorrectly importing zap as `github.com/uber-go/zap` now returns a
+  more informative error.
+
+Thanks to @skipor and @chapsuk for their contributions to this release.
+
+## v1.0.0-rc.1 (14 Feb 2017)
+
+This is the first release candidate for zap's stable release. There are multiple
+breaking changes and improvements from the pre-release version. Most notably:
+
+* **Zap's import path is now "go.uber.org/zap"** &mdash; all users will
+  need to update their code.
+* User-facing types and functions remain in the `zap` package. Code relevant
+  largely to extension authors is now in the `zapcore` package.
+* The `zapcore.Core` type makes it easy for third-party packages to use zap's
+  internals but provide a different user-facing API.
+* `Logger` is now a concrete type instead of an interface.
+* A less verbose (though slower) logging API is included by default.
+* Package-global loggers `L` and `S` are included.
+* A human-friendly console encoder is included.
+* A declarative config struct allows common logger configurations to be managed
+  as configuration instead of code.
+* Sampling is more accurate, and doesn't depend on the standard library's shared
+  timer heap.
+
+## v0.1.0-beta.1 (6 Feb 2017)
+
+This is a minor version, tagged to allow users to pin to the pre-1.0 APIs and
+upgrade at their leisure. Since this is the first tagged release, there are no
+backward compatibility concerns and all functionality is new.
+
+Early zap adopters should pin to the 0.1.x minor version until they're ready to
+upgrade to the upcoming stable release.
+
+[#316]: https://github.com/uber-go/zap/pull/316
+[#309]: https://github.com/uber-go/zap/pull/309
+[#317]: https://github.com/uber-go/zap/pull/317
+[#321]: https://github.com/uber-go/zap/pull/321
+[#325]: https://github.com/uber-go/zap/pull/325
+[#333]: https://github.com/uber-go/zap/pull/333
+[#326]: https://github.com/uber-go/zap/pull/326
+[#300]: https://github.com/uber-go/zap/pull/300
+[#339]: https://github.com/uber-go/zap/pull/339
+[#307]: https://github.com/uber-go/zap/pull/307
+[#353]: https://github.com/uber-go/zap/pull/353
+[#311]: https://github.com/uber-go/zap/pull/311
+[#366]: https://github.com/uber-go/zap/pull/366
+[#364]: https://github.com/uber-go/zap/pull/364
+[#371]: https://github.com/uber-go/zap/pull/371
+[#362]: https://github.com/uber-go/zap/pull/362
+[#369]: https://github.com/uber-go/zap/pull/369
+[#347]: https://github.com/uber-go/zap/pull/347
+[#373]: https://github.com/uber-go/zap/pull/373
+[#348]: https://github.com/uber-go/zap/pull/348
+[#327]: https://github.com/uber-go/zap/pull/327
+[#376]: https://github.com/uber-go/zap/pull/376
+[#346]: https://github.com/uber-go/zap/pull/346
+[#365]: https://github.com/uber-go/zap/pull/365
+[#372]: https://github.com/uber-go/zap/pull/372
+[#385]: https://github.com/uber-go/zap/pull/385
+[#396]: https://github.com/uber-go/zap/pull/396
+[#386]: https://github.com/uber-go/zap/pull/386
+[#402]: https://github.com/uber-go/zap/pull/402
+[#415]: https://github.com/uber-go/zap/pull/415
+[#416]: https://github.com/uber-go/zap/pull/416
+[#424]: https://github.com/uber-go/zap/pull/424
+[#425]: https://github.com/uber-go/zap/pull/425
+[#431]: https://github.com/uber-go/zap/pull/431
+[#435]: https://github.com/uber-go/zap/pull/435
+[#444]: https://github.com/uber-go/zap/pull/444
+[#477]: https://github.com/uber-go/zap/pull/477
+[#465]: https://github.com/uber-go/zap/pull/465
+[#460]: https://github.com/uber-go/zap/pull/460
+[#470]: https://github.com/uber-go/zap/pull/470
+[#487]: https://github.com/uber-go/zap/pull/487
+[#490]: https://github.com/uber-go/zap/pull/490
+[#491]: https://github.com/uber-go/zap/pull/491
+[#491]: https://github.com/uber-go/zap/pull/439
+[#504]: https://github.com/uber-go/zap/pull/504
diff --git a/vendor/go.uber.org/zap/CODE_OF_CONDUCT.md b/vendor/go.uber.org/zap/CODE_OF_CONDUCT.md
new file mode 100644
index 0000000..e327d9a
--- /dev/null
+++ b/vendor/go.uber.org/zap/CODE_OF_CONDUCT.md
@@ -0,0 +1,75 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+In the interest of fostering an open and welcoming environment, we as
+contributors and maintainers pledge to making participation in our project and
+our community a harassment-free experience for everyone, regardless of age,
+body size, disability, ethnicity, gender identity and expression, level of
+experience, nationality, personal appearance, race, religion, or sexual
+identity and orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment
+include:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery and unwelcome sexual attention or
+  advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic
+  address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable
+behavior and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct, or to ban temporarily or
+permanently any contributor for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies both within project spaces and in public spaces
+when an individual is representing the project or its community. Examples of
+representing a project or community include using an official project e-mail
+address, posting via an official social media account, or acting as an
+appointed representative at an online or offline event. Representation of a
+project may be further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting the project team at oss-conduct@uber.com. The project
+team will review and investigate all complaints, and will respond in a way
+that it deems appropriate to the circumstances. The project team is obligated
+to maintain confidentiality with regard to the reporter of an incident.
+Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good
+faith may face temporary or permanent repercussions as determined by other
+members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage],
+version 1.4, available at
+[http://contributor-covenant.org/version/1/4][version].
+
+[homepage]: http://contributor-covenant.org
+[version]: http://contributor-covenant.org/version/1/4/
diff --git a/vendor/go.uber.org/zap/CONTRIBUTING.md b/vendor/go.uber.org/zap/CONTRIBUTING.md
new file mode 100644
index 0000000..9454bba
--- /dev/null
+++ b/vendor/go.uber.org/zap/CONTRIBUTING.md
@@ -0,0 +1,81 @@
+# Contributing
+
+We'd love your help making zap the very best structured logging library in Go!
+
+If you'd like to add new exported APIs, please [open an issue][open-issue]
+describing your proposal &mdash; discussing API changes ahead of time makes
+pull request review much smoother. In your issue, pull request, and any other
+communications, please remember to treat your fellow contributors with
+respect! We take our [code of conduct](CODE_OF_CONDUCT.md) seriously.
+
+Note that you'll need to sign [Uber's Contributor License Agreement][cla]
+before we can accept any of your contributions. If necessary, a bot will remind
+you to accept the CLA when you open your pull request.
+
+## Setup
+
+[Fork][fork], then clone the repository:
+
+```
+mkdir -p $GOPATH/src/go.uber.org
+cd $GOPATH/src/go.uber.org
+git clone git@github.com:your_github_username/zap.git
+cd zap
+git remote add upstream https://github.com/uber-go/zap.git
+git fetch upstream
+```
+
+Install zap's dependencies:
+
+```
+make dependencies
+```
+
+Make sure that the tests and the linters pass:
+
+```
+make test
+make lint
+```
+
+If you're not using the minor version of Go specified in the Makefile's
+`LINTABLE_MINOR_VERSIONS` variable, `make lint` doesn't do anything. This is
+fine, but it means that you'll only discover lint failures after you open your
+pull request.
+
+## Making Changes
+
+Start by creating a new branch for your changes:
+
+```
+cd $GOPATH/src/go.uber.org/zap
+git checkout master
+git fetch upstream
+git rebase upstream/master
+git checkout -b cool_new_feature
+```
+
+Make your changes, then ensure that `make lint` and `make test` still pass. If
+you're satisfied with your changes, push them to your fork.
+
+```
+git push origin cool_new_feature
+```
+
+Then use the GitHub UI to open a pull request.
+
+At this point, you're waiting on us to review your changes. We *try* to respond
+to issues and pull requests within a few business days, and we may suggest some
+improvements or alternatives. Once your changes are approved, one of the
+project maintainers will merge them.
+
+We're much more likely to approve your changes if you:
+
+* Add tests for new functionality.
+* Write a [good commit message][commit-message].
+* Maintain backward compatibility.
+
+[fork]: https://github.com/uber-go/zap/fork
+[open-issue]: https://github.com/uber-go/zap/issues/new
+[cla]: https://cla-assistant.io/uber-go/zap
+[commit-message]: http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html
diff --git a/vendor/go.uber.org/zap/FAQ.md b/vendor/go.uber.org/zap/FAQ.md
new file mode 100644
index 0000000..96e1012
--- /dev/null
+++ b/vendor/go.uber.org/zap/FAQ.md
@@ -0,0 +1,140 @@
+# Frequently Asked Questions
+
+## Design
+
+### Why spend so much effort on logger performance?
+
+Of course, most applications won't notice the impact of a slow logger: they
+already take tens or hundreds of milliseconds for each operation, so an extra
+millisecond doesn't matter.
+
+On the other hand, why *not* make structured logging fast? The `SugaredLogger`
+isn't any harder to use than other logging packages, and the `Logger` makes
+structured logging possible in performance-sensitive contexts. Across a fleet
+of Go microservices, making each application even slightly more efficient adds
+up quickly.
+
+### Why aren't `Logger` and `SugaredLogger` interfaces?
+
+Unlike the familiar `io.Writer` and `http.Handler`, `Logger` and
+`SugaredLogger` interfaces would include *many* methods. As [Rob Pike points
+out][go-proverbs], "The bigger the interface, the weaker the abstraction."
+Interfaces are also rigid &mdash; *any* change requires releasing a new major
+version, since it breaks all third-party implementations.
+
+Making the `Logger` and `SugaredLogger` concrete types doesn't sacrifice much
+abstraction, and it lets us add methods without introducing breaking changes.
+Your applications should define and depend upon an interface that includes
+just the methods you use.
+
+### Why sample application logs?
+
+Applications often experience runs of errors, either because of a bug or
+because of a misbehaving user. Logging errors is usually a good idea, but it
+can easily make this bad situation worse: not only is your application coping
+with a flood of errors, it's also spending extra CPU cycles and I/O logging
+those errors. Since writes are typically serialized, logging limits throughput
+when you need it most.
+
+Sampling fixes this problem by dropping repetitive log entries. Under normal
+conditions, your application writes out every entry. When similar entries are
+logged hundreds or thousands of times each second, though, zap begins dropping
+duplicates to preserve throughput.
+
+### Why do the structured logging APIs take a message in addition to fields?
+
+Subjectively, we find it helpful to accompany structured context with a brief
+description. This isn't critical during development, but it makes debugging
+and operating unfamiliar systems much easier.
+
+More concretely, zap's sampling algorithm uses the message to identify
+duplicate entries. In our experience, this is a practical middle ground
+between random sampling (which often drops the exact entry that you need while
+debugging) and hashing the complete entry (which is prohibitively expensive).
+
+### Why include package-global loggers?
+
+Since so many other logging packages include a global logger, many
+applications aren't designed to accept loggers as explicit parameters.
+Changing function signatures is often a breaking change, so zap includes
+global loggers to simplify migration.
+
+Avoid them where possible.
+
+### Why include dedicated Panic and Fatal log levels?
+
+In general, application code should handle errors gracefully instead of using
+`panic` or `os.Exit`. However, every rule has exceptions, and it's common to
+crash when an error is truly unrecoverable. To avoid losing any information
+&mdash; especially the reason for the crash &mdash; the logger must flush any
+buffered entries before the process exits.
+
+Zap makes this easy by offering `Panic` and `Fatal` logging methods that
+automatically flush before exiting. Of course, this doesn't guarantee that
+logs will never be lost, but it eliminates a common error.
+
+See the discussion in uber-go/zap#207 for more details.
+
+### What's `DPanic`?
+
+`DPanic` stands for "panic in development." In development, it logs at
+`PanicLevel`; otherwise, it logs at `ErrorLevel`. `DPanic` makes it easier to
+catch errors that are theoretically possible, but shouldn't actually happen,
+*without* crashing in production.
+
+If you've ever written code like this, you need `DPanic`:
+
+```go
+if err != nil {
+  panic(fmt.Sprintf("shouldn't ever get here: %v", err))
+}
+```
+
+## Installation
+
+### What does the error `expects import "go.uber.org/zap"` mean?
+
+Either zap was installed incorrectly or you're referencing the wrong package
+name in your code.
+
+Zap's source code happens to be hosted on GitHub, but the [import
+path][import-path] is `go.uber.org/zap`. This gives us, the project
+maintainers, the freedom to move the source code if necessary. However, it
+means that you need to take a little care when installing and using the
+package.
+
+If you follow two simple rules, everything should work: install zap with `go
+get -u go.uber.org/zap`, and always import it in your code with `import
+"go.uber.org/zap"`. Your code shouldn't contain *any* references to
+`github.com/uber-go/zap`.
+
+## Usage
+
+### Does zap support log rotation?
+
+Zap doesn't natively support rotating log files, since we prefer to leave this
+to an external program like `logrotate`.
+
+However, it's easy to integrate a log rotation package like
+[`gopkg.in/natefinch/lumberjack.v2`][lumberjack] as a `zapcore.WriteSyncer`.
+
+```go
+// lumberjack.Logger is already safe for concurrent use, so we don't need to
+// lock it.
+w := zapcore.AddSync(&lumberjack.Logger{
+  Filename:   "/var/log/myapp/foo.log",
+  MaxSize:    500, // megabytes
+  MaxBackups: 3,
+  MaxAge:     28, // days
+})
+core := zapcore.NewCore(
+  zapcore.NewJSONEncoder(zap.NewProductionEncoderConfig()),
+  w,
+  zap.InfoLevel,
+)
+logger := zap.New(core)
+```
+
+[go-proverbs]: https://go-proverbs.github.io/
+[import-path]: https://golang.org/cmd/go/#hdr-Remote_import_paths
+[lumberjack]: https://godoc.org/gopkg.in/natefinch/lumberjack.v2
diff --git a/vendor/go.uber.org/zap/LICENSE.txt b/vendor/go.uber.org/zap/LICENSE.txt
new file mode 100644
index 0000000..6652bed
--- /dev/null
+++ b/vendor/go.uber.org/zap/LICENSE.txt
@@ -0,0 +1,19 @@
+Copyright (c) 2016-2017 Uber Technologies, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/vendor/go.uber.org/zap/Makefile b/vendor/go.uber.org/zap/Makefile
new file mode 100644
index 0000000..8706cd1
--- /dev/null
+++ b/vendor/go.uber.org/zap/Makefile
@@ -0,0 +1,76 @@
+export GO15VENDOREXPERIMENT=1
+
+BENCH_FLAGS ?= -cpuprofile=cpu.pprof -memprofile=mem.pprof -benchmem
+PKGS ?= $(shell glide novendor)
+# Many Go tools take file globs or directories as arguments instead of packages.
+PKG_FILES ?= *.go zapcore benchmarks buffer zapgrpc zaptest zaptest/observer internal/bufferpool internal/exit internal/color
+
+# The linting tools evolve with each Go version, so run them only on the latest
+# stable release.
+GO_VERSION := $(shell go version | cut -d " " -f 3)
+GO_MINOR_VERSION := $(word 2,$(subst ., ,$(GO_VERSION)))
+LINTABLE_MINOR_VERSIONS := 8
+ifneq ($(filter $(LINTABLE_MINOR_VERSIONS),$(GO_MINOR_VERSION)),)
+SHOULD_LINT := true
+endif
+
+
+.PHONY: all
+all: lint test
+
+.PHONY: dependencies
+dependencies:
+	@echo "Installing Glide and locked dependencies..."
+	glide --version || go get -u -f github.com/Masterminds/glide
+	glide install
+	@echo "Installing test dependencies..."
+	go install ./vendor/github.com/axw/gocov/gocov
+	go install ./vendor/github.com/mattn/goveralls
+ifdef SHOULD_LINT
+	@echo "Installing golint..."
+	go install ./vendor/github.com/golang/lint/golint
+else
+	@echo "Not installing golint, since we don't expect to lint on" $(GO_VERSION)
+endif
+
+# Disable printf-like invocation checking due to testify.assert.Error()
+VET_RULES := -printf=false
+
+.PHONY: lint
+lint:
+ifdef SHOULD_LINT
+	@rm -rf lint.log
+	@echo "Checking formatting..."
+	@gofmt -d -s $(PKG_FILES) 2>&1 | tee lint.log
+	@echo "Installing test dependencies for vet..."
+	@go test -i $(PKGS)
+	@echo "Checking vet..."
+	@$(foreach dir,$(PKG_FILES),go tool vet $(VET_RULES) $(dir) 2>&1 | tee -a lint.log;)
+	@echo "Checking lint..."
+	@$(foreach dir,$(PKGS),golint $(dir) 2>&1 | tee -a lint.log;)
+	@echo "Checking for unresolved FIXMEs..."
+	@git grep -i fixme | grep -v -e vendor -e Makefile | tee -a lint.log
+	@echo "Checking for license headers..."
+	@./check_license.sh | tee -a lint.log
+	@[ ! -s lint.log ]
+else
+	@echo "Skipping linters on" $(GO_VERSION)
+endif
+
+.PHONY: test
+test:
+	go test -race $(PKGS)
+
+.PHONY: cover
+cover:
+	./scripts/cover.sh $(PKGS)
+
+.PHONY: bench
+BENCH ?= .
+bench:
+	@$(foreach pkg,$(PKGS),go test -bench=$(BENCH) -run="^$$" $(BENCH_FLAGS) $(pkg);)
+
+.PHONY: updatereadme
+updatereadme:
+	rm -f README.md
+	cat .readme.tmpl | go run internal/readme/readme.go > README.md
diff --git a/vendor/go.uber.org/zap/README.md b/vendor/go.uber.org/zap/README.md
new file mode 100644
index 0000000..4b2bb9d
--- /dev/null
+++ b/vendor/go.uber.org/zap/README.md
@@ -0,0 +1,136 @@
+# :zap: zap [![GoDoc][doc-img]][doc] [![Build Status][ci-img]][ci] [![Coverage Status][cov-img]][cov]
+
+Blazing fast, structured, leveled logging in Go.
+
+## Installation
+
+`go get -u go.uber.org/zap`
+
+Note that zap only supports the two most recent minor versions of Go.
+
+## Quick Start
+
+In contexts where performance is nice, but not critical, use the
+`SugaredLogger`. It's 4-10x faster than than other structured logging
+packages and includes both structured and `printf`-style APIs.
+
+```go
+logger, _ := zap.NewProduction()
+defer logger.Sync() // flushes buffer, if any
+sugar := logger.Sugar()
+sugar.Infow("failed to fetch URL",
+  // Structured context as loosely typed key-value pairs.
+  "url", url,
+  "attempt", 3,
+  "backoff", time.Second,
+)
+sugar.Infof("Failed to fetch URL: %s", url)
+```
+
+When performance and type safety are critical, use the `Logger`. It's even
+faster than the `SugaredLogger` and allocates far less, but it only supports
+structured logging.
+
+```go
+logger, _ := zap.NewProduction()
+defer logger.Sync()
+logger.Info("failed to fetch URL",
+  // Structured context as strongly typed Field values.
+  zap.String("url", url),
+  zap.Int("attempt", 3),
+  zap.Duration("backoff", time.Second),
+)
+```
+
+See the [documentation][doc] and [FAQ](FAQ.md) for more details.
+
+## Performance
+
+For applications that log in the hot path, reflection-based serialization and
+string formatting are prohibitively expensive &mdash; they're CPU-intensive
+and make many small allocations. Put differently, using `encoding/json` and
+`fmt.Fprintf` to log tons of `interface{}`s makes your application slow.
+
+Zap takes a different approach. It includes a reflection-free, zero-allocation
+JSON encoder, and the base `Logger` strives to avoid serialization overhead
+and allocations wherever possible. By building the high-level `SugaredLogger`
+on that foundation, zap lets users *choose* when they need to count every
+allocation and when they'd prefer a more familiar, loosely typed API.
+
+As measured by its own [benchmarking suite][], not only is zap more performant
+than comparable structured logging packages &mdash; it's also faster than the
+standard library. Like all benchmarks, take these with a grain of salt.<sup
+id="anchor-versions">[1](#footnote-versions)</sup>
+
+Log a message and 10 fields:
+
+| Package | Time | Objects Allocated |
+| :--- | :---: | :---: |
+| :zap: zap | 3131 ns/op | 5 allocs/op |
+| :zap: zap (sugared) | 4173 ns/op | 21 allocs/op |
+| zerolog | 16154 ns/op | 90 allocs/op |
+| lion | 16341 ns/op | 111 allocs/op |
+| go-kit | 17049 ns/op | 126 allocs/op |
+| logrus | 23662 ns/op | 142 allocs/op |
+| log15 | 36351 ns/op | 149 allocs/op |
+| apex/log | 42530 ns/op | 126 allocs/op |
+
+Log a message with a logger that already has 10 fields of context:
+
+| Package | Time | Objects Allocated |
+| :--- | :---: | :---: |
+| :zap: zap | 380 ns/op | 0 allocs/op |
+| :zap: zap (sugared) | 564 ns/op | 2 allocs/op |
+| zerolog | 321 ns/op | 0 allocs/op |
+| lion | 7092 ns/op | 39 allocs/op |
+| go-kit | 20226 ns/op | 115 allocs/op |
+| logrus | 22312 ns/op | 130 allocs/op |
+| log15 | 28788 ns/op | 79 allocs/op |
+| apex/log | 42063 ns/op | 115 allocs/op |
+
+Log a static string, without any context or `printf`-style templating:
+
+| Package | Time | Objects Allocated |
+| :--- | :---: | :---: |
+| :zap: zap | 361 ns/op | 0 allocs/op |
+| :zap: zap (sugared) | 534 ns/op | 2 allocs/op |
+| zerolog | 323 ns/op | 0 allocs/op |
+| standard library | 575 ns/op | 2 allocs/op |
+| go-kit | 922 ns/op | 13 allocs/op |
+| lion | 1413 ns/op | 10 allocs/op |
+| logrus | 2291 ns/op | 27 allocs/op |
+| apex/log | 3690 ns/op | 11 allocs/op |
+| log15 | 5954 ns/op | 26 allocs/op |
+
+## Development Status: Stable
+
+All APIs are finalized, and no breaking changes will be made in the 1.x series
+of releases. Users of semver-aware dependency management systems should pin
+zap to `^1`.
+
+## Contributing
+
+We encourage and support an active, healthy community of contributors &mdash;
+including you! Details are in the [contribution guide](CONTRIBUTING.md) and
+the [code of conduct](CODE_OF_CONDUCT.md). The zap maintainers keep an eye on
+issues and pull requests, but you can also report any negative conduct to
+oss-conduct@uber.com. That email list is a private, safe space; even the zap
+maintainers don't have access, so don't hesitate to hold us to a high
+standard.
+
+<hr>
+
+Released under the [MIT License](LICENSE.txt).
+
+<sup id="footnote-versions">1</sup> In particular, keep in mind that we may be
+benchmarking against slightly older versions of other packages. Versions are
+pinned in zap's [glide.lock][] file. [↩](#anchor-versions)
+
+[doc-img]: https://godoc.org/go.uber.org/zap?status.svg
+[doc]: https://godoc.org/go.uber.org/zap
+[ci-img]: https://travis-ci.org/uber-go/zap.svg?branch=master
+[ci]: https://travis-ci.org/uber-go/zap
+[cov-img]: https://codecov.io/gh/uber-go/zap/branch/master/graph/badge.svg
+[cov]: https://codecov.io/gh/uber-go/zap
+[benchmarking suite]: https://github.com/uber-go/zap/tree/master/benchmarks
+[glide.lock]: https://github.com/uber-go/zap/blob/master/glide.lock
diff --git a/vendor/go.uber.org/zap/array.go b/vendor/go.uber.org/zap/array.go
new file mode 100644
index 0000000..3d4d49f
--- /dev/null
+++ b/vendor/go.uber.org/zap/array.go
@@ -0,0 +1,320 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"time"
+
+	"go.uber.org/zap/zapcore"
+)
+
+// Array constructs a field with the given key and ArrayMarshaler. It provides
+// a flexible, but still type-safe and efficient, way to add array-like types
+// to the logging context. The struct's MarshalLogArray method is called lazily.
+func Array(key string, val zapcore.ArrayMarshaler) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.ArrayMarshalerType, Interface: val}
+}
+
+// Bools constructs a field that carries a slice of bools.
+func Bools(key string, bs []bool) zapcore.Field {
+	return Array(key, bools(bs))
+}
+
+// ByteStrings constructs a field that carries a slice of []byte, each of which
+// must be UTF-8 encoded text.
+func ByteStrings(key string, bss [][]byte) zapcore.Field {
+	return Array(key, byteStringsArray(bss))
+}
+
+// Complex128s constructs a field that carries a slice of complex numbers.
+func Complex128s(key string, nums []complex128) zapcore.Field {
+	return Array(key, complex128s(nums))
+}
+
+// Complex64s constructs a field that carries a slice of complex numbers.
+func Complex64s(key string, nums []complex64) zapcore.Field {
+	return Array(key, complex64s(nums))
+}
+
+// Durations constructs a field that carries a slice of time.Durations.
+func Durations(key string, ds []time.Duration) zapcore.Field {
+	return Array(key, durations(ds))
+}
+
+// Float64s constructs a field that carries a slice of floats.
+func Float64s(key string, nums []float64) zapcore.Field {
+	return Array(key, float64s(nums))
+}
+
+// Float32s constructs a field that carries a slice of floats.
+func Float32s(key string, nums []float32) zapcore.Field {
+	return Array(key, float32s(nums))
+}
+
+// Ints constructs a field that carries a slice of integers.
+func Ints(key string, nums []int) zapcore.Field {
+	return Array(key, ints(nums))
+}
+
+// Int64s constructs a field that carries a slice of integers.
+func Int64s(key string, nums []int64) zapcore.Field {
+	return Array(key, int64s(nums))
+}
+
+// Int32s constructs a field that carries a slice of integers.
+func Int32s(key string, nums []int32) zapcore.Field {
+	return Array(key, int32s(nums))
+}
+
+// Int16s constructs a field that carries a slice of integers.
+func Int16s(key string, nums []int16) zapcore.Field {
+	return Array(key, int16s(nums))
+}
+
+// Int8s constructs a field that carries a slice of integers.
+func Int8s(key string, nums []int8) zapcore.Field {
+	return Array(key, int8s(nums))
+}
+
+// Strings constructs a field that carries a slice of strings.
+func Strings(key string, ss []string) zapcore.Field {
+	return Array(key, stringArray(ss))
+}
+
+// Times constructs a field that carries a slice of time.Times.
+func Times(key string, ts []time.Time) zapcore.Field {
+	return Array(key, times(ts))
+}
+
+// Uints constructs a field that carries a slice of unsigned integers.
+func Uints(key string, nums []uint) zapcore.Field {
+	return Array(key, uints(nums))
+}
+
+// Uint64s constructs a field that carries a slice of unsigned integers.
+func Uint64s(key string, nums []uint64) zapcore.Field {
+	return Array(key, uint64s(nums))
+}
+
+// Uint32s constructs a field that carries a slice of unsigned integers.
+func Uint32s(key string, nums []uint32) zapcore.Field {
+	return Array(key, uint32s(nums))
+}
+
+// Uint16s constructs a field that carries a slice of unsigned integers.
+func Uint16s(key string, nums []uint16) zapcore.Field {
+	return Array(key, uint16s(nums))
+}
+
+// Uint8s constructs a field that carries a slice of unsigned integers.
+func Uint8s(key string, nums []uint8) zapcore.Field {
+	return Array(key, uint8s(nums))
+}
+
+// Uintptrs constructs a field that carries a slice of pointer addresses.
+func Uintptrs(key string, us []uintptr) zapcore.Field {
+	return Array(key, uintptrs(us))
+}
+
+// Errors constructs a field that carries a slice of errors.
+func Errors(key string, errs []error) zapcore.Field {
+	return Array(key, errArray(errs))
+}
+
+type bools []bool
+
+func (bs bools) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range bs {
+		arr.AppendBool(bs[i])
+	}
+	return nil
+}
+
+type byteStringsArray [][]byte
+
+func (bss byteStringsArray) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range bss {
+		arr.AppendByteString(bss[i])
+	}
+	return nil
+}
+
+type complex128s []complex128
+
+func (nums complex128s) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range nums {
+		arr.AppendComplex128(nums[i])
+	}
+	return nil
+}
+
+type complex64s []complex64
+
+func (nums complex64s) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range nums {
+		arr.AppendComplex64(nums[i])
+	}
+	return nil
+}
+
+type durations []time.Duration
+
+func (ds durations) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range ds {
+		arr.AppendDuration(ds[i])
+	}
+	return nil
+}
+
+type float64s []float64
+
+func (nums float64s) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range nums {
+		arr.AppendFloat64(nums[i])
+	}
+	return nil
+}
+
+type float32s []float32
+
+func (nums float32s) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range nums {
+		arr.AppendFloat32(nums[i])
+	}
+	return nil
+}
+
+type ints []int
+
+func (nums ints) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range nums {
+		arr.AppendInt(nums[i])
+	}
+	return nil
+}
+
+type int64s []int64
+
+func (nums int64s) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range nums {
+		arr.AppendInt64(nums[i])
+	}
+	return nil
+}
+
+type int32s []int32
+
+func (nums int32s) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range nums {
+		arr.AppendInt32(nums[i])
+	}
+	return nil
+}
+
+type int16s []int16
+
+func (nums int16s) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range nums {
+		arr.AppendInt16(nums[i])
+	}
+	return nil
+}
+
+type int8s []int8
+
+func (nums int8s) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range nums {
+		arr.AppendInt8(nums[i])
+	}
+	return nil
+}
+
+type stringArray []string
+
+func (ss stringArray) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range ss {
+		arr.AppendString(ss[i])
+	}
+	return nil
+}
+
+type times []time.Time
+
+func (ts times) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range ts {
+		arr.AppendTime(ts[i])
+	}
+	return nil
+}
+
+type uints []uint
+
+func (nums uints) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range nums {
+		arr.AppendUint(nums[i])
+	}
+	return nil
+}
+
+type uint64s []uint64
+
+func (nums uint64s) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range nums {
+		arr.AppendUint64(nums[i])
+	}
+	return nil
+}
+
+type uint32s []uint32
+
+func (nums uint32s) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range nums {
+		arr.AppendUint32(nums[i])
+	}
+	return nil
+}
+
+type uint16s []uint16
+
+func (nums uint16s) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range nums {
+		arr.AppendUint16(nums[i])
+	}
+	return nil
+}
+
+type uint8s []uint8
+
+func (nums uint8s) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range nums {
+		arr.AppendUint8(nums[i])
+	}
+	return nil
+}
+
+type uintptrs []uintptr
+
+func (nums uintptrs) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range nums {
+		arr.AppendUintptr(nums[i])
+	}
+	return nil
+}
diff --git a/vendor/go.uber.org/zap/array_test.go b/vendor/go.uber.org/zap/array_test.go
new file mode 100644
index 0000000..df84d92
--- /dev/null
+++ b/vendor/go.uber.org/zap/array_test.go
@@ -0,0 +1,107 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"testing"
+	"time"
+
+	"go.uber.org/zap/zapcore"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func BenchmarkBoolsArrayMarshaler(b *testing.B) {
+	// Keep this benchmark here to capture the overhead of the ArrayMarshaler
+	// wrapper.
+	bs := make([]bool, 50)
+	enc := zapcore.NewJSONEncoder(zapcore.EncoderConfig{})
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Bools("array", bs).AddTo(enc.Clone())
+	}
+}
+
+func BenchmarkBoolsReflect(b *testing.B) {
+	bs := make([]bool, 50)
+	enc := zapcore.NewJSONEncoder(zapcore.EncoderConfig{})
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Reflect("array", bs).AddTo(enc.Clone())
+	}
+}
+
+func TestArrayWrappers(t *testing.T) {
+	tests := []struct {
+		desc     string
+		field    zapcore.Field
+		expected []interface{}
+	}{
+		{"empty bools", Bools("", []bool{}), []interface{}(nil)},
+		{"empty byte strings", ByteStrings("", [][]byte{}), []interface{}(nil)},
+		{"empty complex128s", Complex128s("", []complex128{}), []interface{}(nil)},
+		{"empty complex64s", Complex64s("", []complex64{}), []interface{}(nil)},
+		{"empty durations", Durations("", []time.Duration{}), []interface{}(nil)},
+		{"empty float64s", Float64s("", []float64{}), []interface{}(nil)},
+		{"empty float32s", Float32s("", []float32{}), []interface{}(nil)},
+		{"empty ints", Ints("", []int{}), []interface{}(nil)},
+		{"empty int64s", Int64s("", []int64{}), []interface{}(nil)},
+		{"empty int32s", Int32s("", []int32{}), []interface{}(nil)},
+		{"empty int16s", Int16s("", []int16{}), []interface{}(nil)},
+		{"empty int8s", Int8s("", []int8{}), []interface{}(nil)},
+		{"empty strings", Strings("", []string{}), []interface{}(nil)},
+		{"empty times", Times("", []time.Time{}), []interface{}(nil)},
+		{"empty uints", Uints("", []uint{}), []interface{}(nil)},
+		{"empty uint64s", Uint64s("", []uint64{}), []interface{}(nil)},
+		{"empty uint32s", Uint32s("", []uint32{}), []interface{}(nil)},
+		{"empty uint16s", Uint16s("", []uint16{}), []interface{}(nil)},
+		{"empty uint8s", Uint8s("", []uint8{}), []interface{}(nil)},
+		{"empty uintptrs", Uintptrs("", []uintptr{}), []interface{}(nil)},
+		{"bools", Bools("", []bool{true, false}), []interface{}{true, false}},
+		{"byte strings", ByteStrings("", [][]byte{{1, 2}, {3, 4}}), []interface{}{[]byte{1, 2}, []byte{3, 4}}},
+		{"complex128s", Complex128s("", []complex128{1 + 2i, 3 + 4i}), []interface{}{1 + 2i, 3 + 4i}},
+		{"complex64s", Complex64s("", []complex64{1 + 2i, 3 + 4i}), []interface{}{complex64(1 + 2i), complex64(3 + 4i)}},
+		{"durations", Durations("", []time.Duration{1, 2}), []interface{}{time.Nanosecond, 2 * time.Nanosecond}},
+		{"float64s", Float64s("", []float64{1.2, 3.4}), []interface{}{1.2, 3.4}},
+		{"float32s", Float32s("", []float32{1.2, 3.4}), []interface{}{float32(1.2), float32(3.4)}},
+		{"ints", Ints("", []int{1, 2}), []interface{}{1, 2}},
+		{"int64s", Int64s("", []int64{1, 2}), []interface{}{int64(1), int64(2)}},
+		{"int32s", Int32s("", []int32{1, 2}), []interface{}{int32(1), int32(2)}},
+		{"int16s", Int16s("", []int16{1, 2}), []interface{}{int16(1), int16(2)}},
+		{"int8s", Int8s("", []int8{1, 2}), []interface{}{int8(1), int8(2)}},
+		{"strings", Strings("", []string{"foo", "bar"}), []interface{}{"foo", "bar"}},
+		{"times", Times("", []time.Time{time.Unix(0, 0), time.Unix(0, 0)}), []interface{}{time.Unix(0, 0), time.Unix(0, 0)}},
+		{"uints", Uints("", []uint{1, 2}), []interface{}{uint(1), uint(2)}},
+		{"uint64s", Uint64s("", []uint64{1, 2}), []interface{}{uint64(1), uint64(2)}},
+		{"uint32s", Uint32s("", []uint32{1, 2}), []interface{}{uint32(1), uint32(2)}},
+		{"uint16s", Uint16s("", []uint16{1, 2}), []interface{}{uint16(1), uint16(2)}},
+		{"uint8s", Uint8s("", []uint8{1, 2}), []interface{}{uint8(1), uint8(2)}},
+		{"uintptrs", Uintptrs("", []uintptr{1, 2}), []interface{}{uintptr(1), uintptr(2)}},
+	}
+
+	for _, tt := range tests {
+		enc := zapcore.NewMapObjectEncoder()
+		tt.field.Key = "k"
+		tt.field.AddTo(enc)
+		assert.Equal(t, tt.expected, enc.Fields["k"], "%s: unexpected map contents.", tt.desc)
+		assert.Equal(t, 1, len(enc.Fields), "%s: found extra keys in map: %v", tt.desc, enc.Fields)
+	}
+}
diff --git a/vendor/go.uber.org/zap/benchmarks/apex_test.go b/vendor/go.uber.org/zap/benchmarks/apex_test.go
new file mode 100644
index 0000000..67d7646
--- /dev/null
+++ b/vendor/go.uber.org/zap/benchmarks/apex_test.go
@@ -0,0 +1,57 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package benchmarks
+
+import (
+	"io/ioutil"
+
+	"github.com/apex/log"
+	"github.com/apex/log/handlers/json"
+)
+
+func newDisabledApexLog() *log.Logger {
+	return &log.Logger{
+		Handler: json.New(ioutil.Discard),
+		Level:   log.ErrorLevel,
+	}
+}
+
+func newApexLog() *log.Logger {
+	return &log.Logger{
+		Handler: json.New(ioutil.Discard),
+		Level:   log.DebugLevel,
+	}
+}
+
+func fakeApexFields() log.Fields {
+	return log.Fields{
+		"int":     _tenInts[0],
+		"ints":    _tenInts,
+		"string":  _tenStrings[0],
+		"strings": _tenStrings,
+		"time":    _tenTimes[0],
+		"times":   _tenTimes,
+		"user1":   _oneUser,
+		"user2":   _oneUser,
+		"users":   _tenUsers,
+		"error":   errExample,
+	}
+}
diff --git a/vendor/go.uber.org/zap/benchmarks/doc.go b/vendor/go.uber.org/zap/benchmarks/doc.go
new file mode 100644
index 0000000..b79f79f
--- /dev/null
+++ b/vendor/go.uber.org/zap/benchmarks/doc.go
@@ -0,0 +1,23 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Package benchmarks contains only benchmarks comparing zap to other
+// structured logging libraries.
+package benchmarks
diff --git a/vendor/go.uber.org/zap/benchmarks/kit_test.go b/vendor/go.uber.org/zap/benchmarks/kit_test.go
new file mode 100644
index 0000000..b9da293
--- /dev/null
+++ b/vendor/go.uber.org/zap/benchmarks/kit_test.go
@@ -0,0 +1,31 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package benchmarks
+
+import (
+	"io/ioutil"
+
+	"github.com/go-kit/kit/log"
+)
+
+func newKitLog(fields ...interface{}) log.Logger {
+	return log.With(log.NewJSONLogger(ioutil.Discard), fields...)
+}
diff --git a/vendor/go.uber.org/zap/benchmarks/lion_test.go b/vendor/go.uber.org/zap/benchmarks/lion_test.go
new file mode 100644
index 0000000..6c41cb1
--- /dev/null
+++ b/vendor/go.uber.org/zap/benchmarks/lion_test.go
@@ -0,0 +1,31 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package benchmarks
+
+import (
+	"io/ioutil"
+
+	"go.pedge.io/lion"
+)
+
+func newLion() lion.Logger {
+	return lion.NewLogger(lion.NewJSONWritePusher(ioutil.Discard))
+}
diff --git a/vendor/go.uber.org/zap/benchmarks/log15_test.go b/vendor/go.uber.org/zap/benchmarks/log15_test.go
new file mode 100644
index 0000000..70a60b3
--- /dev/null
+++ b/vendor/go.uber.org/zap/benchmarks/log15_test.go
@@ -0,0 +1,33 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package benchmarks
+
+import (
+	"io/ioutil"
+
+	"gopkg.in/inconshreveable/log15.v2"
+)
+
+func newLog15() log15.Logger {
+	logger := log15.New()
+	logger.SetHandler(log15.StreamHandler(ioutil.Discard, log15.JsonFormat()))
+	return logger
+}
diff --git a/vendor/go.uber.org/zap/benchmarks/logrus_test.go b/vendor/go.uber.org/zap/benchmarks/logrus_test.go
new file mode 100644
index 0000000..ee684a6
--- /dev/null
+++ b/vendor/go.uber.org/zap/benchmarks/logrus_test.go
@@ -0,0 +1,57 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package benchmarks
+
+import (
+	"io/ioutil"
+
+	"github.com/sirupsen/logrus"
+)
+
+func newDisabledLogrus() *logrus.Logger {
+	logger := newLogrus()
+	logger.Level = logrus.ErrorLevel
+	return logger
+}
+
+func newLogrus() *logrus.Logger {
+	return &logrus.Logger{
+		Out:       ioutil.Discard,
+		Formatter: new(logrus.JSONFormatter),
+		Hooks:     make(logrus.LevelHooks),
+		Level:     logrus.DebugLevel,
+	}
+}
+
+func fakeLogrusFields() logrus.Fields {
+	return logrus.Fields{
+		"int":     _tenInts[0],
+		"ints":    _tenInts,
+		"string":  _tenStrings[0],
+		"strings": _tenStrings,
+		"time":    _tenTimes[0],
+		"times":   _tenTimes,
+		"user1":   _oneUser,
+		"user2":   _oneUser,
+		"users":   _tenUsers,
+		"error":   errExample,
+	}
+}
diff --git a/vendor/go.uber.org/zap/benchmarks/scenario_bench_test.go b/vendor/go.uber.org/zap/benchmarks/scenario_bench_test.go
new file mode 100644
index 0000000..4e307d2
--- /dev/null
+++ b/vendor/go.uber.org/zap/benchmarks/scenario_bench_test.go
@@ -0,0 +1,614 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package benchmarks
+
+import (
+	"io/ioutil"
+	"log"
+	"testing"
+
+	"go.uber.org/zap"
+)
+
+func BenchmarkDisabledWithoutFields(b *testing.B) {
+	b.Logf("Logging at a disabled level without any structured context.")
+	b.Run("Zap", func(b *testing.B) {
+		logger := newZapLogger(zap.ErrorLevel)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("Zap.Check", func(b *testing.B) {
+		logger := newZapLogger(zap.ErrorLevel)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				if m := logger.Check(zap.InfoLevel, getMessage(0)); m != nil {
+					m.Write()
+				}
+			}
+		})
+	})
+	b.Run("Zap.Sugar", func(b *testing.B) {
+		logger := newZapLogger(zap.ErrorLevel).Sugar()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("Zap.SugarFormatting", func(b *testing.B) {
+		logger := newZapLogger(zap.ErrorLevel).Sugar()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Infof("%v %v %v %s %v %v %v %v %v %s\n", fakeFmtArgs()...)
+			}
+		})
+	})
+	b.Run("apex/log", func(b *testing.B) {
+		logger := newDisabledApexLog()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("sirupsen/logrus", func(b *testing.B) {
+		logger := newDisabledLogrus()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("rs/zerolog", func(b *testing.B) {
+		logger := newDisabledZerolog()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info().Msg(getMessage(0))
+			}
+		})
+	})
+}
+
+func BenchmarkDisabledAccumulatedContext(b *testing.B) {
+	b.Logf("Logging at a disabled level with some accumulated context.")
+	b.Run("Zap", func(b *testing.B) {
+		logger := newZapLogger(zap.ErrorLevel).With(fakeFields()...)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("Zap.Check", func(b *testing.B) {
+		logger := newZapLogger(zap.ErrorLevel).With(fakeFields()...)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				if m := logger.Check(zap.InfoLevel, getMessage(0)); m != nil {
+					m.Write()
+				}
+			}
+		})
+	})
+	b.Run("Zap.Sugar", func(b *testing.B) {
+		logger := newZapLogger(zap.ErrorLevel).With(fakeFields()...).Sugar()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("Zap.SugarFormatting", func(b *testing.B) {
+		logger := newZapLogger(zap.ErrorLevel).With(fakeFields()...).Sugar()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Infof("%v %v %v %s %v %v %v %v %v %s\n", fakeFmtArgs()...)
+			}
+		})
+	})
+	b.Run("apex/log", func(b *testing.B) {
+		logger := newDisabledApexLog().WithFields(fakeApexFields())
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("sirupsen/logrus", func(b *testing.B) {
+		logger := newDisabledLogrus().WithFields(fakeLogrusFields())
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("rs/zerolog", func(b *testing.B) {
+		logger := fakeZerologContext(newDisabledZerolog().With()).Logger()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info().Msg(getMessage(0))
+			}
+		})
+	})
+}
+
+func BenchmarkDisabledAddingFields(b *testing.B) {
+	b.Logf("Logging at a disabled level, adding context at each log site.")
+	b.Run("Zap", func(b *testing.B) {
+		logger := newZapLogger(zap.ErrorLevel)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0), fakeFields()...)
+			}
+		})
+	})
+	b.Run("Zap.Check", func(b *testing.B) {
+		logger := newZapLogger(zap.ErrorLevel)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				if m := logger.Check(zap.InfoLevel, getMessage(0)); m != nil {
+					m.Write(fakeFields()...)
+				}
+			}
+		})
+	})
+	b.Run("Zap.Sugar", func(b *testing.B) {
+		logger := newZapLogger(zap.ErrorLevel).Sugar()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Infow(getMessage(0), fakeSugarFields()...)
+			}
+		})
+	})
+	b.Run("apex/log", func(b *testing.B) {
+		logger := newDisabledApexLog()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.WithFields(fakeApexFields()).Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("sirupsen/logrus", func(b *testing.B) {
+		logger := newDisabledLogrus()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.WithFields(fakeLogrusFields()).Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("rs/zerolog", func(b *testing.B) {
+		logger := newDisabledZerolog()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				fakeZerologFields(logger.Info()).Msg(getMessage(0))
+			}
+		})
+	})
+}
+
+func BenchmarkWithoutFields(b *testing.B) {
+	b.Logf("Logging without any structured context.")
+	b.Run("Zap", func(b *testing.B) {
+		logger := newZapLogger(zap.DebugLevel)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("Zap.Check", func(b *testing.B) {
+		logger := newZapLogger(zap.DebugLevel)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				if ce := logger.Check(zap.InfoLevel, getMessage(0)); ce != nil {
+					ce.Write()
+				}
+			}
+		})
+	})
+	b.Run("Zap.CheckSampled", func(b *testing.B) {
+		logger := newSampledLogger(zap.DebugLevel)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			i := 0
+			for pb.Next() {
+				i++
+				if ce := logger.Check(zap.InfoLevel, getMessage(i)); ce != nil {
+					ce.Write()
+				}
+			}
+		})
+	})
+	b.Run("Zap.Sugar", func(b *testing.B) {
+		logger := newZapLogger(zap.DebugLevel).Sugar()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("Zap.SugarFormatting", func(b *testing.B) {
+		logger := newZapLogger(zap.DebugLevel).Sugar()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Infof("%v %v %v %s %v %v %v %v %v %s\n", fakeFmtArgs()...)
+			}
+		})
+	})
+	b.Run("apex/log", func(b *testing.B) {
+		logger := newApexLog()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("go-kit/kit/log", func(b *testing.B) {
+		logger := newKitLog()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Log(getMessage(0), getMessage(1))
+			}
+		})
+	})
+	b.Run("inconshreveable/log15", func(b *testing.B) {
+		logger := newLog15()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("sirupsen/logrus", func(b *testing.B) {
+		logger := newLogrus()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("go.pedge.io/lion", func(b *testing.B) {
+		logger := newLion()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Printf(getMessage(0))
+			}
+		})
+	})
+	b.Run("stdlib.Println", func(b *testing.B) {
+		logger := log.New(ioutil.Discard, "", log.LstdFlags)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Println(getMessage(0))
+			}
+		})
+	})
+	b.Run("stdlib.Printf", func(b *testing.B) {
+		logger := log.New(ioutil.Discard, "", log.LstdFlags)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Printf("%v %v %v %s %v %v %v %v %v %s\n", fakeFmtArgs()...)
+			}
+		})
+	})
+	b.Run("rs/zerolog", func(b *testing.B) {
+		logger := newZerolog()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info().Msg(getMessage(0))
+			}
+		})
+	})
+	b.Run("rs/zerolog.Formatting", func(b *testing.B) {
+		logger := newZerolog()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info().Msgf("%v %v %v %s %v %v %v %v %v %s\n", fakeFmtArgs()...)
+			}
+		})
+	})
+	b.Run("rs/zerolog.Check", func(b *testing.B) {
+		logger := newZerolog()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				if e := logger.Info(); e.Enabled() {
+					e.Msg(getMessage(0))
+				}
+			}
+		})
+	})
+}
+
+func BenchmarkAccumulatedContext(b *testing.B) {
+	b.Logf("Logging with some accumulated context.")
+	b.Run("Zap", func(b *testing.B) {
+		logger := newZapLogger(zap.DebugLevel).With(fakeFields()...)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("Zap.Check", func(b *testing.B) {
+		logger := newZapLogger(zap.DebugLevel).With(fakeFields()...)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				if ce := logger.Check(zap.InfoLevel, getMessage(0)); ce != nil {
+					ce.Write()
+				}
+			}
+		})
+	})
+	b.Run("Zap.CheckSampled", func(b *testing.B) {
+		logger := newSampledLogger(zap.DebugLevel).With(fakeFields()...)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			i := 0
+			for pb.Next() {
+				i++
+				if ce := logger.Check(zap.InfoLevel, getMessage(i)); ce != nil {
+					ce.Write()
+				}
+			}
+		})
+	})
+	b.Run("Zap.Sugar", func(b *testing.B) {
+		logger := newZapLogger(zap.DebugLevel).With(fakeFields()...).Sugar()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("Zap.SugarFormatting", func(b *testing.B) {
+		logger := newZapLogger(zap.DebugLevel).With(fakeFields()...).Sugar()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Infof("%v %v %v %s %v %v %v %v %v %s\n", fakeFmtArgs()...)
+			}
+		})
+	})
+	b.Run("apex/log", func(b *testing.B) {
+		logger := newApexLog().WithFields(fakeApexFields())
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("go-kit/kit/log", func(b *testing.B) {
+		logger := newKitLog(fakeSugarFields()...)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Log(getMessage(0), getMessage(1))
+			}
+		})
+	})
+	b.Run("inconshreveable/log15", func(b *testing.B) {
+		logger := newLog15().New(fakeSugarFields())
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("sirupsen/logrus", func(b *testing.B) {
+		logger := newLogrus().WithFields(fakeLogrusFields())
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("go.pedge.io/lion", func(b *testing.B) {
+		logger := newLion().WithFields(fakeLogrusFields())
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Infof(getMessage(0))
+			}
+		})
+	})
+	b.Run("rs/zerolog", func(b *testing.B) {
+		logger := fakeZerologContext(newZerolog().With()).Logger()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info().Msg(getMessage(0))
+			}
+		})
+	})
+	b.Run("rs/zerolog.Check", func(b *testing.B) {
+		logger := fakeZerologContext(newZerolog().With()).Logger()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				if e := logger.Info(); e.Enabled() {
+					e.Msg(getMessage(0))
+				}
+			}
+		})
+	})
+	b.Run("rs/zerolog.Formatting", func(b *testing.B) {
+		logger := fakeZerologContext(newZerolog().With()).Logger()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info().Msgf("%v %v %v %s %v %v %v %v %v %s\n", fakeFmtArgs()...)
+			}
+		})
+	})
+}
+
+func BenchmarkAddingFields(b *testing.B) {
+	b.Logf("Logging with additional context at each log site.")
+	b.Run("Zap", func(b *testing.B) {
+		logger := newZapLogger(zap.DebugLevel)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0), fakeFields()...)
+			}
+		})
+	})
+	b.Run("Zap.Check", func(b *testing.B) {
+		logger := newZapLogger(zap.DebugLevel)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				if ce := logger.Check(zap.InfoLevel, getMessage(0)); ce != nil {
+					ce.Write(fakeFields()...)
+				}
+			}
+		})
+	})
+	b.Run("Zap.CheckSampled", func(b *testing.B) {
+		logger := newSampledLogger(zap.DebugLevel)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			i := 0
+			for pb.Next() {
+				i++
+				if ce := logger.Check(zap.InfoLevel, getMessage(i)); ce != nil {
+					ce.Write(fakeFields()...)
+				}
+			}
+		})
+	})
+	b.Run("Zap.Sugar", func(b *testing.B) {
+		logger := newZapLogger(zap.DebugLevel).Sugar()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Infow(getMessage(0), fakeSugarFields()...)
+			}
+		})
+	})
+	b.Run("apex/log", func(b *testing.B) {
+		logger := newApexLog()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.WithFields(fakeApexFields()).Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("go-kit/kit/log", func(b *testing.B) {
+		logger := newKitLog()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Log(fakeSugarFields()...)
+			}
+		})
+	})
+	b.Run("inconshreveable/log15", func(b *testing.B) {
+		logger := newLog15()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.Info(getMessage(0), fakeSugarFields()...)
+			}
+		})
+	})
+	b.Run("sirupsen/logrus", func(b *testing.B) {
+		logger := newLogrus()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.WithFields(fakeLogrusFields()).Info(getMessage(0))
+			}
+		})
+	})
+	b.Run("go.pedge.io/lion", func(b *testing.B) {
+		logger := newLion()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				logger.WithFields(fakeLogrusFields()).Infof(getMessage(0))
+			}
+		})
+	})
+	b.Run("rs/zerolog", func(b *testing.B) {
+		logger := newZerolog()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				fakeZerologFields(logger.Info()).Msg(getMessage(0))
+			}
+		})
+	})
+	b.Run("rs/zerolog.Check", func(b *testing.B) {
+		logger := newZerolog()
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				if e := logger.Info(); e.Enabled() {
+					fakeZerologFields(e).Msg(getMessage(0))
+				}
+			}
+		})
+	})
+}
diff --git a/vendor/go.uber.org/zap/benchmarks/zap_test.go b/vendor/go.uber.org/zap/benchmarks/zap_test.go
new file mode 100644
index 0000000..294260b
--- /dev/null
+++ b/vendor/go.uber.org/zap/benchmarks/zap_test.go
@@ -0,0 +1,172 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package benchmarks
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"go.uber.org/multierr"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest"
+)
+
+var (
+	errExample = errors.New("fail")
+
+	_messages   = fakeMessages(1000)
+	_tenInts    = []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 0}
+	_tenStrings = []string{"a", "b", "c", "d", "e", "f", "g", "h", "i", "j"}
+	_tenTimes   = []time.Time{
+		time.Unix(0, 0),
+		time.Unix(1, 0),
+		time.Unix(2, 0),
+		time.Unix(3, 0),
+		time.Unix(4, 0),
+		time.Unix(5, 0),
+		time.Unix(6, 0),
+		time.Unix(7, 0),
+		time.Unix(8, 0),
+		time.Unix(9, 0),
+	}
+	_oneUser = &user{
+		Name:      "Jane Doe",
+		Email:     "jane@test.com",
+		CreatedAt: time.Date(1980, 1, 1, 12, 0, 0, 0, time.UTC),
+	}
+	_tenUsers = users{
+		_oneUser,
+		_oneUser,
+		_oneUser,
+		_oneUser,
+		_oneUser,
+		_oneUser,
+		_oneUser,
+		_oneUser,
+		_oneUser,
+		_oneUser,
+	}
+)
+
+func fakeMessages(n int) []string {
+	messages := make([]string, n)
+	for i := range messages {
+		messages[i] = fmt.Sprintf("Test logging, but use a somewhat realistic message length. (#%v)", i)
+	}
+	return messages
+}
+
+func getMessage(iter int) string {
+	return _messages[iter%1000]
+}
+
+type users []*user
+
+func (uu users) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	var err error
+	for i := range uu {
+		err = multierr.Append(err, arr.AppendObject(uu[i]))
+	}
+	return err
+}
+
+type user struct {
+	Name      string    `json:"name"`
+	Email     string    `json:"email"`
+	CreatedAt time.Time `json:"created_at"`
+}
+
+func (u *user) MarshalLogObject(enc zapcore.ObjectEncoder) error {
+	enc.AddString("name", u.Name)
+	enc.AddString("email", u.Email)
+	enc.AddInt64("createdAt", u.CreatedAt.UnixNano())
+	return nil
+}
+
+func newZapLogger(lvl zapcore.Level) *zap.Logger {
+	ec := zap.NewProductionEncoderConfig()
+	ec.EncodeDuration = zapcore.NanosDurationEncoder
+	ec.EncodeTime = zapcore.EpochNanosTimeEncoder
+	enc := zapcore.NewJSONEncoder(ec)
+	return zap.New(zapcore.NewCore(
+		enc,
+		&zaptest.Discarder{},
+		lvl,
+	))
+}
+
+func newSampledLogger(lvl zapcore.Level) *zap.Logger {
+	return zap.New(zapcore.NewSampler(
+		newZapLogger(zap.DebugLevel).Core(),
+		100*time.Millisecond,
+		10, // first
+		10, // thereafter
+	))
+}
+
+func fakeFields() []zapcore.Field {
+	return []zapcore.Field{
+		zap.Int("int", _tenInts[0]),
+		zap.Ints("ints", _tenInts),
+		zap.String("string", _tenStrings[0]),
+		zap.Strings("strings", _tenStrings),
+		zap.Time("time", _tenTimes[0]),
+		zap.Times("times", _tenTimes),
+		zap.Object("user1", _oneUser),
+		zap.Object("user2", _oneUser),
+		zap.Array("users", _tenUsers),
+		zap.Error(errExample),
+	}
+}
+
+func fakeSugarFields() []interface{} {
+	return []interface{}{
+		"int", _tenInts[0],
+		"ints", _tenInts,
+		"string", _tenStrings[0],
+		"strings", _tenStrings,
+		"time", _tenTimes[0],
+		"times", _tenTimes,
+		"user1", _oneUser,
+		"user2", _oneUser,
+		"users", _tenUsers,
+		"error", errExample,
+	}
+}
+
+func fakeFmtArgs() []interface{} {
+	// Need to keep this a function instead of a package-global var so that we
+	// pay the cast-to-interface{} penalty on each call.
+	return []interface{}{
+		_tenInts[0],
+		_tenInts,
+		_tenStrings[0],
+		_tenStrings,
+		_tenTimes[0],
+		_tenTimes,
+		_oneUser,
+		_oneUser,
+		_tenUsers,
+		errExample,
+	}
+}
diff --git a/vendor/go.uber.org/zap/benchmarks/zerolog_test.go b/vendor/go.uber.org/zap/benchmarks/zerolog_test.go
new file mode 100644
index 0000000..b14cd9d
--- /dev/null
+++ b/vendor/go.uber.org/zap/benchmarks/zerolog_test.go
@@ -0,0 +1,63 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package benchmarks
+
+import (
+	"io/ioutil"
+
+	"github.com/rs/zerolog"
+)
+
+func newZerolog() zerolog.Logger {
+	return zerolog.New(ioutil.Discard).With().Timestamp().Logger()
+}
+
+func newDisabledZerolog() zerolog.Logger {
+	return newZerolog().Level(zerolog.Disabled)
+}
+
+func fakeZerologFields(e *zerolog.Event) *zerolog.Event {
+	return e.
+		Int("int", _tenInts[0]).
+		Interface("ints", _tenInts).
+		Str("string", _tenStrings[0]).
+		Interface("strings", _tenStrings).
+		Time("time", _tenTimes[0]).
+		Interface("times", _tenTimes).
+		Interface("user1", _oneUser).
+		Interface("user2", _oneUser).
+		Interface("users", _tenUsers).
+		Err(errExample)
+}
+
+func fakeZerologContext(c zerolog.Context) zerolog.Context {
+	return c.
+		Int("int", _tenInts[0]).
+		Interface("ints", _tenInts).
+		Str("string", _tenStrings[0]).
+		Interface("strings", _tenStrings).
+		Time("time", _tenTimes[0]).
+		Interface("times", _tenTimes).
+		Interface("user1", _oneUser).
+		Interface("user2", _oneUser).
+		Interface("users", _tenUsers).
+		Err(errExample)
+}
diff --git a/vendor/go.uber.org/zap/buffer/buffer.go b/vendor/go.uber.org/zap/buffer/buffer.go
new file mode 100644
index 0000000..ea6fdc8
--- /dev/null
+++ b/vendor/go.uber.org/zap/buffer/buffer.go
@@ -0,0 +1,106 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Package buffer provides a thin wrapper around a byte slice. Unlike the
+// standard library's bytes.Buffer, it supports a portion of the strconv
+// package's zero-allocation formatters.
+package buffer
+
+import "strconv"
+
+const _size = 1024 // by default, create 1 KiB buffers
+
+// Buffer is a thin wrapper around a byte slice. It's intended to be pooled, so
+// the only way to construct one is via a Pool.
+type Buffer struct {
+	bs   []byte
+	pool Pool
+}
+
+// AppendByte writes a single byte to the Buffer.
+func (b *Buffer) AppendByte(v byte) {
+	b.bs = append(b.bs, v)
+}
+
+// AppendString writes a string to the Buffer.
+func (b *Buffer) AppendString(s string) {
+	b.bs = append(b.bs, s...)
+}
+
+// AppendInt appends an integer to the underlying buffer (assuming base 10).
+func (b *Buffer) AppendInt(i int64) {
+	b.bs = strconv.AppendInt(b.bs, i, 10)
+}
+
+// AppendUint appends an unsigned integer to the underlying buffer (assuming
+// base 10).
+func (b *Buffer) AppendUint(i uint64) {
+	b.bs = strconv.AppendUint(b.bs, i, 10)
+}
+
+// AppendBool appends a bool to the underlying buffer.
+func (b *Buffer) AppendBool(v bool) {
+	b.bs = strconv.AppendBool(b.bs, v)
+}
+
+// AppendFloat appends a float to the underlying buffer. It doesn't quote NaN
+// or +/- Inf.
+func (b *Buffer) AppendFloat(f float64, bitSize int) {
+	b.bs = strconv.AppendFloat(b.bs, f, 'f', -1, bitSize)
+}
+
+// Len returns the length of the underlying byte slice.
+func (b *Buffer) Len() int {
+	return len(b.bs)
+}
+
+// Cap returns the capacity of the underlying byte slice.
+func (b *Buffer) Cap() int {
+	return cap(b.bs)
+}
+
+// Bytes returns a mutable reference to the underlying byte slice.
+func (b *Buffer) Bytes() []byte {
+	return b.bs
+}
+
+// String returns a string copy of the underlying byte slice.
+func (b *Buffer) String() string {
+	return string(b.bs)
+}
+
+// Reset resets the underlying byte slice. Subsequent writes re-use the slice's
+// backing array.
+func (b *Buffer) Reset() {
+	b.bs = b.bs[:0]
+}
+
+// Write implements io.Writer.
+func (b *Buffer) Write(bs []byte) (int, error) {
+	b.bs = append(b.bs, bs...)
+	return len(bs), nil
+}
+
+// Free returns the Buffer to its Pool.
+//
+// Callers must not retain references to the Buffer after calling Free.
+func (b *Buffer) Free() {
+	b.pool.put(b)
+}
diff --git a/vendor/go.uber.org/zap/buffer/buffer_test.go b/vendor/go.uber.org/zap/buffer/buffer_test.go
new file mode 100644
index 0000000..59bc08a
--- /dev/null
+++ b/vendor/go.uber.org/zap/buffer/buffer_test.go
@@ -0,0 +1,91 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package buffer
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestBufferWrites(t *testing.T) {
+	buf := NewPool().Get()
+
+	tests := []struct {
+		desc string
+		f    func()
+		want string
+	}{
+		{"AppendByte", func() { buf.AppendByte('v') }, "v"},
+		{"AppendString", func() { buf.AppendString("foo") }, "foo"},
+		{"AppendIntPositive", func() { buf.AppendInt(42) }, "42"},
+		{"AppendIntNegative", func() { buf.AppendInt(-42) }, "-42"},
+		{"AppendUint", func() { buf.AppendUint(42) }, "42"},
+		{"AppendBool", func() { buf.AppendBool(true) }, "true"},
+		{"AppendFloat64", func() { buf.AppendFloat(3.14, 64) }, "3.14"},
+		// Intenationally introduce some floating-point error.
+		{"AppendFloat32", func() { buf.AppendFloat(float64(float32(3.14)), 32) }, "3.14"},
+		{"AppendWrite", func() { buf.Write([]byte("foo")) }, "foo"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.desc, func(t *testing.T) {
+			buf.Reset()
+			tt.f()
+			assert.Equal(t, tt.want, buf.String(), "Unexpected buffer.String().")
+			assert.Equal(t, tt.want, string(buf.Bytes()), "Unexpected string(buffer.Bytes()).")
+			assert.Equal(t, len(tt.want), buf.Len(), "Unexpected buffer length.")
+			// We're not writing more than a kibibyte in tests.
+			assert.Equal(t, _size, buf.Cap(), "Expected buffer capacity to remain constant.")
+		})
+	}
+}
+
+func BenchmarkBuffers(b *testing.B) {
+	// Because we use the strconv.AppendFoo functions so liberally, we can't
+	// use the standard library's bytes.Buffer anyways (without incurring a
+	// bunch of extra allocations). Nevertheless, let's make sure that we're
+	// not losing any precious nanoseconds.
+	str := strings.Repeat("a", 1024)
+	slice := make([]byte, 1024)
+	buf := bytes.NewBuffer(slice)
+	custom := NewPool().Get()
+	b.Run("ByteSlice", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			slice = append(slice, str...)
+			slice = slice[:0]
+		}
+	})
+	b.Run("BytesBuffer", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			buf.WriteString(str)
+			buf.Reset()
+		}
+	})
+	b.Run("CustomBuffer", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			custom.AppendString(str)
+			custom.Reset()
+		}
+	})
+}
diff --git a/vendor/go.uber.org/zap/buffer/pool.go b/vendor/go.uber.org/zap/buffer/pool.go
new file mode 100644
index 0000000..8fb3e20
--- /dev/null
+++ b/vendor/go.uber.org/zap/buffer/pool.go
@@ -0,0 +1,49 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package buffer
+
+import "sync"
+
+// A Pool is a type-safe wrapper around a sync.Pool.
+type Pool struct {
+	p *sync.Pool
+}
+
+// NewPool constructs a new Pool.
+func NewPool() Pool {
+	return Pool{p: &sync.Pool{
+		New: func() interface{} {
+			return &Buffer{bs: make([]byte, 0, _size)}
+		},
+	}}
+}
+
+// Get retrieves a Buffer from the pool, creating one if necessary.
+func (p Pool) Get() *Buffer {
+	buf := p.p.Get().(*Buffer)
+	buf.Reset()
+	buf.pool = p
+	return buf
+}
+
+func (p Pool) put(buf *Buffer) {
+	p.p.Put(buf)
+}
diff --git a/vendor/go.uber.org/zap/buffer/pool_test.go b/vendor/go.uber.org/zap/buffer/pool_test.go
new file mode 100644
index 0000000..a219815
--- /dev/null
+++ b/vendor/go.uber.org/zap/buffer/pool_test.go
@@ -0,0 +1,52 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package buffer
+
+import (
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestBuffers(t *testing.T) {
+	const dummyData = "dummy data"
+	p := NewPool()
+
+	var wg sync.WaitGroup
+	for g := 0; g < 10; g++ {
+		wg.Add(1)
+		go func() {
+			for i := 0; i < 100; i++ {
+				buf := p.Get()
+				assert.Zero(t, buf.Len(), "Expected truncated buffer")
+				assert.NotZero(t, buf.Cap(), "Expected non-zero capacity")
+
+				buf.AppendString(dummyData)
+				assert.Equal(t, buf.Len(), len(dummyData), "Expected buffer to contain dummy data")
+
+				buf.Free()
+			}
+			wg.Done()
+		}()
+	}
+	wg.Wait()
+}
diff --git a/vendor/go.uber.org/zap/check_license.sh b/vendor/go.uber.org/zap/check_license.sh
new file mode 100755
index 0000000..345ac8b
--- /dev/null
+++ b/vendor/go.uber.org/zap/check_license.sh
@@ -0,0 +1,17 @@
+#!/bin/bash -e
+
+ERROR_COUNT=0
+while read -r file
+do
+	case "$(head -1 "${file}")" in
+		*"Copyright (c) "*" Uber Technologies, Inc.")
+			# everything's cool
+			;;
+		*)
+			echo "$file is missing license header."
+			(( ERROR_COUNT++ ))
+			;;
+	esac
+done < <(git ls-files "*\.go")
+
+exit $ERROR_COUNT
diff --git a/vendor/go.uber.org/zap/common_test.go b/vendor/go.uber.org/zap/common_test.go
new file mode 100644
index 0000000..b0a4a2e
--- /dev/null
+++ b/vendor/go.uber.org/zap/common_test.go
@@ -0,0 +1,57 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"sync"
+	"testing"
+
+	"go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest/observer"
+)
+
+func opts(opts ...Option) []Option {
+	return opts
+}
+
+// Here specifically to introduce an easily-identifiable filename for testing
+// stacktraces and caller skips.
+func withLogger(t testing.TB, e zapcore.LevelEnabler, opts []Option, f func(*Logger, *observer.ObservedLogs)) {
+	fac, logs := observer.New(e)
+	log := New(fac, opts...)
+	f(log, logs)
+}
+
+func withSugar(t testing.TB, e zapcore.LevelEnabler, opts []Option, f func(*SugaredLogger, *observer.ObservedLogs)) {
+	withLogger(t, e, opts, func(logger *Logger, logs *observer.ObservedLogs) { f(logger.Sugar(), logs) })
+}
+
+func runConcurrently(goroutines, iterations int, wg *sync.WaitGroup, f func()) {
+	wg.Add(goroutines)
+	for g := 0; g < goroutines; g++ {
+		go func() {
+			defer wg.Done()
+			for i := 0; i < iterations; i++ {
+				f()
+			}
+		}()
+	}
+}
diff --git a/vendor/go.uber.org/zap/config.go b/vendor/go.uber.org/zap/config.go
new file mode 100644
index 0000000..b0658ed
--- /dev/null
+++ b/vendor/go.uber.org/zap/config.go
@@ -0,0 +1,243 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"sort"
+	"time"
+
+	"go.uber.org/zap/zapcore"
+)
+
+// SamplingConfig sets a sampling strategy for the logger. Sampling caps the
+// global CPU and I/O load that logging puts on your process while attempting
+// to preserve a representative subset of your logs.
+//
+// Values configured here are per-second. See zapcore.NewSampler for details.
+type SamplingConfig struct {
+	Initial    int `json:"initial" yaml:"initial"`
+	Thereafter int `json:"thereafter" yaml:"thereafter"`
+}
+
+// Config offers a declarative way to construct a logger. It doesn't do
+// anything that can't be done with New, Options, and the various
+// zapcore.WriteSyncer and zapcore.Core wrappers, but it's a simpler way to
+// toggle common options.
+//
+// Note that Config intentionally supports only the most common options. More
+// unusual logging setups (logging to network connections or message queues,
+// splitting output between multiple files, etc.) are possible, but require
+// direct use of the zapcore package. For sample code, see the package-level
+// BasicConfiguration and AdvancedConfiguration examples.
+//
+// For an example showing runtime log level changes, see the documentation for
+// AtomicLevel.
+type Config struct {
+	// Level is the minimum enabled logging level. Note that this is a dynamic
+	// level, so calling Config.Level.SetLevel will atomically change the log
+	// level of all loggers descended from this config.
+	Level AtomicLevel `json:"level" yaml:"level"`
+	// Development puts the logger in development mode, which changes the
+	// behavior of DPanicLevel and takes stacktraces more liberally.
+	Development bool `json:"development" yaml:"development"`
+	// DisableCaller stops annotating logs with the calling function's file
+	// name and line number. By default, all logs are annotated.
+	DisableCaller bool `json:"disableCaller" yaml:"disableCaller"`
+	// DisableStacktrace completely disables automatic stacktrace capturing. By
+	// default, stacktraces are captured for WarnLevel and above logs in
+	// development and ErrorLevel and above in production.
+	DisableStacktrace bool `json:"disableStacktrace" yaml:"disableStacktrace"`
+	// Sampling sets a sampling policy. A nil SamplingConfig disables sampling.
+	Sampling *SamplingConfig `json:"sampling" yaml:"sampling"`
+	// Encoding sets the logger's encoding. Valid values are "json" and
+	// "console", as well as any third-party encodings registered via
+	// RegisterEncoder.
+	Encoding string `json:"encoding" yaml:"encoding"`
+	// EncoderConfig sets options for the chosen encoder. See
+	// zapcore.EncoderConfig for details.
+	EncoderConfig zapcore.EncoderConfig `json:"encoderConfig" yaml:"encoderConfig"`
+	// OutputPaths is a list of paths to write logging output to. See Open for
+	// details.
+	OutputPaths []string `json:"outputPaths" yaml:"outputPaths"`
+	// ErrorOutputPaths is a list of paths to write internal logger errors to.
+	// The default is standard error.
+	//
+	// Note that this setting only affects internal errors; for sample code that
+	// sends error-level logs to a different location from info- and debug-level
+	// logs, see the package-level AdvancedConfiguration example.
+	ErrorOutputPaths []string `json:"errorOutputPaths" yaml:"errorOutputPaths"`
+	// InitialFields is a collection of fields to add to the root logger.
+	InitialFields map[string]interface{} `json:"initialFields" yaml:"initialFields"`
+}
+
+// NewProductionEncoderConfig returns an opinionated EncoderConfig for
+// production environments.
+func NewProductionEncoderConfig() zapcore.EncoderConfig {
+	return zapcore.EncoderConfig{
+		TimeKey:        "ts",
+		LevelKey:       "level",
+		NameKey:        "logger",
+		CallerKey:      "caller",
+		MessageKey:     "msg",
+		StacktraceKey:  "stacktrace",
+		LineEnding:     zapcore.DefaultLineEnding,
+		EncodeLevel:    zapcore.LowercaseLevelEncoder,
+		EncodeTime:     zapcore.EpochTimeEncoder,
+		EncodeDuration: zapcore.SecondsDurationEncoder,
+		EncodeCaller:   zapcore.ShortCallerEncoder,
+	}
+}
+
+// NewProductionConfig is a reasonable production logging configuration.
+// Logging is enabled at InfoLevel and above.
+//
+// It uses a JSON encoder, writes to standard error, and enables sampling.
+// Stacktraces are automatically included on logs of ErrorLevel and above.
+func NewProductionConfig() Config {
+	return Config{
+		Level:       NewAtomicLevelAt(InfoLevel),
+		Development: false,
+		Sampling: &SamplingConfig{
+			Initial:    100,
+			Thereafter: 100,
+		},
+		Encoding:         "json",
+		EncoderConfig:    NewProductionEncoderConfig(),
+		OutputPaths:      []string{"stderr"},
+		ErrorOutputPaths: []string{"stderr"},
+	}
+}
+
+// NewDevelopmentEncoderConfig returns an opinionated EncoderConfig for
+// development environments.
+func NewDevelopmentEncoderConfig() zapcore.EncoderConfig {
+	return zapcore.EncoderConfig{
+		// Keys can be anything except the empty string.
+		TimeKey:        "T",
+		LevelKey:       "L",
+		NameKey:        "N",
+		CallerKey:      "C",
+		MessageKey:     "M",
+		StacktraceKey:  "S",
+		LineEnding:     zapcore.DefaultLineEnding,
+		EncodeLevel:    zapcore.CapitalLevelEncoder,
+		EncodeTime:     zapcore.ISO8601TimeEncoder,
+		EncodeDuration: zapcore.StringDurationEncoder,
+		EncodeCaller:   zapcore.ShortCallerEncoder,
+	}
+}
+
+// NewDevelopmentConfig is a reasonable development logging configuration.
+// Logging is enabled at DebugLevel and above.
+//
+// It enables development mode (which makes DPanicLevel logs panic), uses a
+// console encoder, writes to standard error, and disables sampling.
+// Stacktraces are automatically included on logs of WarnLevel and above.
+func NewDevelopmentConfig() Config {
+	return Config{
+		Level:            NewAtomicLevelAt(DebugLevel),
+		Development:      true,
+		Encoding:         "console",
+		EncoderConfig:    NewDevelopmentEncoderConfig(),
+		OutputPaths:      []string{"stderr"},
+		ErrorOutputPaths: []string{"stderr"},
+	}
+}
+
+// Build constructs a logger from the Config and Options.
+func (cfg Config) Build(opts ...Option) (*Logger, error) {
+	enc, err := cfg.buildEncoder()
+	if err != nil {
+		return nil, err
+	}
+
+	sink, errSink, err := cfg.openSinks()
+	if err != nil {
+		return nil, err
+	}
+
+	log := New(
+		zapcore.NewCore(enc, sink, cfg.Level),
+		cfg.buildOptions(errSink)...,
+	)
+	if len(opts) > 0 {
+		log = log.WithOptions(opts...)
+	}
+	return log, nil
+}
+
+func (cfg Config) buildOptions(errSink zapcore.WriteSyncer) []Option {
+	opts := []Option{ErrorOutput(errSink)}
+
+	if cfg.Development {
+		opts = append(opts, Development())
+	}
+
+	if !cfg.DisableCaller {
+		opts = append(opts, AddCaller())
+	}
+
+	stackLevel := ErrorLevel
+	if cfg.Development {
+		stackLevel = WarnLevel
+	}
+	if !cfg.DisableStacktrace {
+		opts = append(opts, AddStacktrace(stackLevel))
+	}
+
+	if cfg.Sampling != nil {
+		opts = append(opts, WrapCore(func(core zapcore.Core) zapcore.Core {
+			return zapcore.NewSampler(core, time.Second, int(cfg.Sampling.Initial), int(cfg.Sampling.Thereafter))
+		}))
+	}
+
+	if len(cfg.InitialFields) > 0 {
+		fs := make([]zapcore.Field, 0, len(cfg.InitialFields))
+		keys := make([]string, 0, len(cfg.InitialFields))
+		for k := range cfg.InitialFields {
+			keys = append(keys, k)
+		}
+		sort.Strings(keys)
+		for _, k := range keys {
+			fs = append(fs, Any(k, cfg.InitialFields[k]))
+		}
+		opts = append(opts, Fields(fs...))
+	}
+
+	return opts
+}
+
+func (cfg Config) openSinks() (zapcore.WriteSyncer, zapcore.WriteSyncer, error) {
+	sink, closeOut, err := Open(cfg.OutputPaths...)
+	if err != nil {
+		return nil, nil, err
+	}
+	errSink, _, err := Open(cfg.ErrorOutputPaths...)
+	if err != nil {
+		closeOut()
+		return nil, nil, err
+	}
+	return sink, errSink, nil
+}
+
+func (cfg Config) buildEncoder() (zapcore.Encoder, error) {
+	return newEncoder(cfg.Encoding, cfg.EncoderConfig)
+}
diff --git a/vendor/go.uber.org/zap/config_test.go b/vendor/go.uber.org/zap/config_test.go
new file mode 100644
index 0000000..7a87570
--- /dev/null
+++ b/vendor/go.uber.org/zap/config_test.go
@@ -0,0 +1,108 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestConfig(t *testing.T) {
+	tests := []struct {
+		desc     string
+		cfg      Config
+		expectN  int64
+		expectRe string
+	}{
+		{
+			desc:    "production",
+			cfg:     NewProductionConfig(),
+			expectN: 2 + 100 + 1, // 2 from initial logs, 100 initial sampled logs, 1 from off-by-one in sampler
+			expectRe: `{"level":"info","caller":"zap/config_test.go:\d+","msg":"info","k":"v","z":"zz"}` + "\n" +
+				`{"level":"warn","caller":"zap/config_test.go:\d+","msg":"warn","k":"v","z":"zz"}` + "\n",
+		},
+		{
+			desc:    "development",
+			cfg:     NewDevelopmentConfig(),
+			expectN: 3 + 200, // 3 initial logs, all 200 subsequent logs
+			expectRe: "DEBUG\tzap/config_test.go:" + `\d+` + "\tdebug\t" + `{"k": "v", "z": "zz"}` + "\n" +
+				"INFO\tzap/config_test.go:" + `\d+` + "\tinfo\t" + `{"k": "v", "z": "zz"}` + "\n" +
+				"WARN\tzap/config_test.go:" + `\d+` + "\twarn\t" + `{"k": "v", "z": "zz"}` + "\n" +
+				`testing.\w+`,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.desc, func(t *testing.T) {
+			temp, err := ioutil.TempFile("", "zap-prod-config-test")
+			require.NoError(t, err, "Failed to create temp file.")
+			defer os.Remove(temp.Name())
+
+			tt.cfg.OutputPaths = []string{temp.Name()}
+			tt.cfg.EncoderConfig.TimeKey = "" // no timestamps in tests
+			tt.cfg.InitialFields = map[string]interface{}{"z": "zz", "k": "v"}
+
+			hook, count := makeCountingHook()
+			logger, err := tt.cfg.Build(Hooks(hook))
+			require.NoError(t, err, "Unexpected error constructing logger.")
+
+			logger.Debug("debug")
+			logger.Info("info")
+			logger.Warn("warn")
+
+			byteContents, err := ioutil.ReadAll(temp)
+			require.NoError(t, err, "Couldn't read log contents from temp file.")
+			logs := string(byteContents)
+			assert.Regexp(t, tt.expectRe, logs, "Unexpected log output.")
+
+			for i := 0; i < 200; i++ {
+				logger.Info("sampling")
+			}
+			assert.Equal(t, tt.expectN, count.Load(), "Hook called an unexpected number of times.")
+		})
+	}
+}
+
+func TestConfigWithInvalidPaths(t *testing.T) {
+	tests := []struct {
+		desc      string
+		output    string
+		errOutput string
+	}{
+		{"output directory doesn't exist", "/tmp/not-there/foo.log", "stderr"},
+		{"error output directory doesn't exist", "stdout", "/tmp/not-there/foo-errors.log"},
+		{"neither output directory exists", "/tmp/not-there/foo.log", "/tmp/not-there/foo-errors.log"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.desc, func(t *testing.T) {
+			cfg := NewProductionConfig()
+			cfg.OutputPaths = []string{tt.output}
+			cfg.ErrorOutputPaths = []string{tt.errOutput}
+			_, err := cfg.Build()
+			assert.Error(t, err, "Expected an error opening a non-existent directory.")
+		})
+	}
+}
diff --git a/vendor/go.uber.org/zap/doc.go b/vendor/go.uber.org/zap/doc.go
new file mode 100644
index 0000000..3f16a8d
--- /dev/null
+++ b/vendor/go.uber.org/zap/doc.go
@@ -0,0 +1,113 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Package zap provides fast, structured, leveled logging.
+//
+// For applications that log in the hot path, reflection-based serialization
+// and string formatting are prohibitively expensive - they're CPU-intensive
+// and make many small allocations. Put differently, using json.Marshal and
+// fmt.Fprintf to log tons of interface{} makes your application slow.
+//
+// Zap takes a different approach. It includes a reflection-free,
+// zero-allocation JSON encoder, and the base Logger strives to avoid
+// serialization overhead and allocations wherever possible. By building the
+// high-level SugaredLogger on that foundation, zap lets users choose when
+// they need to count every allocation and when they'd prefer a more familiar,
+// loosely typed API.
+//
+// Choosing a Logger
+//
+// In contexts where performance is nice, but not critical, use the
+// SugaredLogger. It's 4-10x faster than other structured logging packages and
+// supports both structured and printf-style logging. Like log15 and go-kit,
+// the SugaredLogger's structured logging APIs are loosely typed and accept a
+// variadic number of key-value pairs. (For more advanced use cases, they also
+// accept strongly typed fields - see the SugaredLogger.With documentation for
+// details.)
+//  sugar := zap.NewExample().Sugar()
+//  defer sugar.Sync()
+//  sugar.Infow("failed to fetch URL",
+//    "url", "http://example.com",
+//    "attempt", 3,
+//    "backoff", time.Second,
+//  )
+//  sugar.Printf("failed to fetch URL: %s", "http://example.com")
+//
+// By default, loggers are unbuffered. However, since zap's low-level APIs
+// allow buffering, calling Sync before letting your process exit is a good
+// habit.
+//
+// In the rare contexts where every microsecond and every allocation matter,
+// use the Logger. It's even faster than the SugaredLogger and allocates far
+// less, but it only supports strongly-typed, structured logging.
+//  logger := zap.NewExample()
+//  defer logger.Sync()
+//  logger.Info("failed to fetch URL",
+//    zap.String("url", "http://example.com"),
+//    zap.Int("attempt", 3),
+//    zap.Duration("backoff", time.Second),
+//  )
+//
+// Choosing between the Logger and SugaredLogger doesn't need to be an
+// application-wide decision: converting between the two is simple and
+// inexpensive.
+//   logger := zap.NewExample()
+//   defer logger.Sync()
+//   sugar := logger.Sugar()
+//   plain := sugar.Desugar()
+//
+// Configuring Zap
+//
+// The simplest way to build a Logger is to use zap's opinionated presets:
+// NewExample, NewProduction, and NewDevelopment. These presets build a logger
+// with a single function call:
+//  logger, err := zap.NewProduction()
+//  if err != nil {
+//    log.Fatalf("can't initialize zap logger: %v", err)
+//  }
+//  defer logger.Sync()
+//
+// Presets are fine for small projects, but larger projects and organizations
+// naturally require a bit more customization. For most users, zap's Config
+// struct strikes the right balance between flexibility and convenience. See
+// the package-level BasicConfiguration example for sample code.
+//
+// More unusual configurations (splitting output between files, sending logs
+// to a message queue, etc.) are possible, but require direct use of
+// go.uber.org/zap/zapcore. See the package-level AdvancedConfiguration
+// example for sample code.
+//
+// Extending Zap
+//
+// The zap package itself is a relatively thin wrapper around the interfaces
+// in go.uber.org/zap/zapcore. Extending zap to support a new encoding (e.g.,
+// BSON), a new log sink (e.g., Kafka), or something more exotic (perhaps an
+// exception aggregation service, like Sentry or Rollbar) typically requires
+// implementing the zapcore.Encoder, zapcore.WriteSyncer, or zapcore.Core
+// interfaces. See the zapcore documentation for details.
+//
+// Similarly, package authors can use the high-performance Encoder and Core
+// implementations in the zapcore package to build their own loggers.
+//
+// Frequently Asked Questions
+//
+// An FAQ covering everything from installation errors to design decisions is
+// available at https://github.com/uber-go/zap/blob/master/FAQ.md.
+package zap // import "go.uber.org/zap"
diff --git a/vendor/go.uber.org/zap/encoder.go b/vendor/go.uber.org/zap/encoder.go
new file mode 100644
index 0000000..2e9d3c3
--- /dev/null
+++ b/vendor/go.uber.org/zap/encoder.go
@@ -0,0 +1,75 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+
+	"go.uber.org/zap/zapcore"
+)
+
+var (
+	errNoEncoderNameSpecified = errors.New("no encoder name specified")
+
+	_encoderNameToConstructor = map[string]func(zapcore.EncoderConfig) (zapcore.Encoder, error){
+		"console": func(encoderConfig zapcore.EncoderConfig) (zapcore.Encoder, error) {
+			return zapcore.NewConsoleEncoder(encoderConfig), nil
+		},
+		"json": func(encoderConfig zapcore.EncoderConfig) (zapcore.Encoder, error) {
+			return zapcore.NewJSONEncoder(encoderConfig), nil
+		},
+	}
+	_encoderMutex sync.RWMutex
+)
+
+// RegisterEncoder registers an encoder constructor, which the Config struct
+// can then reference. By default, the "json" and "console" encoders are
+// registered.
+//
+// Attempting to register an encoder whose name is already taken returns an
+// error.
+func RegisterEncoder(name string, constructor func(zapcore.EncoderConfig) (zapcore.Encoder, error)) error {
+	_encoderMutex.Lock()
+	defer _encoderMutex.Unlock()
+	if name == "" {
+		return errNoEncoderNameSpecified
+	}
+	if _, ok := _encoderNameToConstructor[name]; ok {
+		return fmt.Errorf("encoder already registered for name %q", name)
+	}
+	_encoderNameToConstructor[name] = constructor
+	return nil
+}
+
+func newEncoder(name string, encoderConfig zapcore.EncoderConfig) (zapcore.Encoder, error) {
+	_encoderMutex.RLock()
+	defer _encoderMutex.RUnlock()
+	if name == "" {
+		return nil, errNoEncoderNameSpecified
+	}
+	constructor, ok := _encoderNameToConstructor[name]
+	if !ok {
+		return nil, fmt.Errorf("no encoder registered for name %q", name)
+	}
+	return constructor(encoderConfig)
+}
diff --git a/vendor/go.uber.org/zap/encoder_test.go b/vendor/go.uber.org/zap/encoder_test.go
new file mode 100644
index 0000000..f6be665
--- /dev/null
+++ b/vendor/go.uber.org/zap/encoder_test.go
@@ -0,0 +1,88 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"testing"
+
+	"go.uber.org/zap/zapcore"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRegisterDefaultEncoders(t *testing.T) {
+	testEncodersRegistered(t, "console", "json")
+}
+
+func TestRegisterEncoder(t *testing.T) {
+	testEncoders(func() {
+		assert.NoError(t, RegisterEncoder("foo", newNilEncoder), "expected to be able to register the encoder foo")
+		testEncodersRegistered(t, "foo")
+	})
+}
+
+func TestDuplicateRegisterEncoder(t *testing.T) {
+	testEncoders(func() {
+		RegisterEncoder("foo", newNilEncoder)
+		assert.Error(t, RegisterEncoder("foo", newNilEncoder), "expected an error when registering an encoder with the same name twice")
+	})
+}
+
+func TestRegisterEncoderNoName(t *testing.T) {
+	assert.Equal(t, errNoEncoderNameSpecified, RegisterEncoder("", newNilEncoder), "expected an error when registering an encoder with no name")
+}
+
+func TestNewEncoder(t *testing.T) {
+	testEncoders(func() {
+		RegisterEncoder("foo", newNilEncoder)
+		encoder, err := newEncoder("foo", zapcore.EncoderConfig{})
+		assert.NoError(t, err, "could not create an encoder for the registered name foo")
+		assert.Nil(t, encoder, "the encoder from newNilEncoder is not nil")
+	})
+}
+
+func TestNewEncoderNotRegistered(t *testing.T) {
+	_, err := newEncoder("foo", zapcore.EncoderConfig{})
+	assert.Error(t, err, "expected an error when trying to create an encoder of an unregistered name")
+}
+
+func TestNewEncoderNoName(t *testing.T) {
+	_, err := newEncoder("", zapcore.EncoderConfig{})
+	assert.Equal(t, errNoEncoderNameSpecified, err, "expected an error when creating an encoder with no name")
+}
+
+func testEncoders(f func()) {
+	existing := _encoderNameToConstructor
+	_encoderNameToConstructor = make(map[string]func(zapcore.EncoderConfig) (zapcore.Encoder, error))
+	defer func() { _encoderNameToConstructor = existing }()
+	f()
+}
+
+func testEncodersRegistered(t *testing.T, names ...string) {
+	assert.Len(t, _encoderNameToConstructor, len(names), "the expected number of registered encoders does not match the actual number")
+	for _, name := range names {
+		assert.NotNil(t, _encoderNameToConstructor[name], "no encoder is registered for name %s", name)
+	}
+}
+
+func newNilEncoder(_ zapcore.EncoderConfig) (zapcore.Encoder, error) {
+	return nil, nil
+}
diff --git a/vendor/go.uber.org/zap/error.go b/vendor/go.uber.org/zap/error.go
new file mode 100644
index 0000000..2bff30d
--- /dev/null
+++ b/vendor/go.uber.org/zap/error.go
@@ -0,0 +1,80 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"sync"
+
+	"go.uber.org/zap/zapcore"
+)
+
+var _errArrayElemPool = sync.Pool{New: func() interface{} {
+	return &errArrayElem{}
+}}
+
+// Error is shorthand for the common idiom NamedError("error", err).
+func Error(err error) zapcore.Field {
+	return NamedError("error", err)
+}
+
+// NamedError constructs a field that lazily stores err.Error() under the
+// provided key. Errors which also implement fmt.Formatter (like those produced
+// by github.com/pkg/errors) will also have their verbose representation stored
+// under key+"Verbose". If passed a nil error, the field is a no-op.
+//
+// For the common case in which the key is simply "error", the Error function
+// is shorter and less repetitive.
+func NamedError(key string, err error) zapcore.Field {
+	if err == nil {
+		return Skip()
+	}
+	return zapcore.Field{Key: key, Type: zapcore.ErrorType, Interface: err}
+}
+
+type errArray []error
+
+func (errs errArray) MarshalLogArray(arr zapcore.ArrayEncoder) error {
+	for i := range errs {
+		if errs[i] == nil {
+			continue
+		}
+		// To represent each error as an object with an "error" attribute and
+		// potentially an "errorVerbose" attribute, we need to wrap it in a
+		// type that implements LogObjectMarshaler. To prevent this from
+		// allocating, pool the wrapper type.
+		elem := _errArrayElemPool.Get().(*errArrayElem)
+		elem.error = errs[i]
+		arr.AppendObject(elem)
+		elem.error = nil
+		_errArrayElemPool.Put(elem)
+	}
+	return nil
+}
+
+type errArrayElem struct {
+	error
+}
+
+func (e *errArrayElem) MarshalLogObject(enc zapcore.ObjectEncoder) error {
+	// Re-use the error field's logic, which supports non-standard error types.
+	Error(e.error).AddTo(enc)
+	return nil
+}
diff --git a/vendor/go.uber.org/zap/error_test.go b/vendor/go.uber.org/zap/error_test.go
new file mode 100644
index 0000000..54ce4bb
--- /dev/null
+++ b/vendor/go.uber.org/zap/error_test.go
@@ -0,0 +1,99 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"errors"
+	"testing"
+
+	"go.uber.org/zap/zapcore"
+
+	richErrors "github.com/pkg/errors"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestErrorConstructors(t *testing.T) {
+	fail := errors.New("fail")
+
+	tests := []struct {
+		name   string
+		field  zapcore.Field
+		expect zapcore.Field
+	}{
+		{"Error", Skip(), Error(nil)},
+		{"Error", zapcore.Field{Key: "error", Type: zapcore.ErrorType, Interface: fail}, Error(fail)},
+		{"NamedError", Skip(), NamedError("foo", nil)},
+		{"NamedError", zapcore.Field{Key: "foo", Type: zapcore.ErrorType, Interface: fail}, NamedError("foo", fail)},
+		{"Any:Error", Any("k", errors.New("v")), NamedError("k", errors.New("v"))},
+		{"Any:Errors", Any("k", []error{errors.New("v")}), Errors("k", []error{errors.New("v")})},
+	}
+
+	for _, tt := range tests {
+		if !assert.Equal(t, tt.expect, tt.field, "Unexpected output from convenience field constructor %s.", tt.name) {
+			t.Logf("type expected: %T\nGot: %T", tt.expect.Interface, tt.field.Interface)
+		}
+		assertCanBeReused(t, tt.field)
+	}
+}
+
+func TestErrorArrayConstructor(t *testing.T) {
+	tests := []struct {
+		desc     string
+		field    zapcore.Field
+		expected []interface{}
+	}{
+		{"empty errors", Errors("", []error{}), []interface{}(nil)},
+		{
+			"errors",
+			Errors("", []error{nil, errors.New("foo"), nil, errors.New("bar")}),
+			[]interface{}{map[string]interface{}{"error": "foo"}, map[string]interface{}{"error": "bar"}},
+		},
+	}
+
+	for _, tt := range tests {
+		enc := zapcore.NewMapObjectEncoder()
+		tt.field.Key = "k"
+		tt.field.AddTo(enc)
+		assert.Equal(t, tt.expected, enc.Fields["k"], "%s: unexpected map contents.", tt.desc)
+		assert.Equal(t, 1, len(enc.Fields), "%s: found extra keys in map: %v", tt.desc, enc.Fields)
+	}
+}
+
+func TestErrorsArraysHandleRichErrors(t *testing.T) {
+	errs := []error{richErrors.New("egad")}
+
+	enc := zapcore.NewMapObjectEncoder()
+	Errors("k", errs).AddTo(enc)
+	assert.Equal(t, 1, len(enc.Fields), "Expected only top-level field.")
+
+	val := enc.Fields["k"]
+	arr, ok := val.([]interface{})
+	require.True(t, ok, "Expected top-level field to be an array.")
+	require.Equal(t, 1, len(arr), "Expected only one error object in array.")
+
+	serialized := arr[0]
+	errMap, ok := serialized.(map[string]interface{})
+	require.True(t, ok, "Expected serialized error to be a map, got %T.", serialized)
+	assert.Equal(t, "egad", errMap["error"], "Unexpected standard error string.")
+	assert.Contains(t, errMap["errorVerbose"], "egad", "Verbose error string should be a superset of standard error.")
+	assert.Contains(t, errMap["errorVerbose"], "TestErrorsArraysHandleRichErrors", "Verbose error string should contain a stacktrace.")
+}
diff --git a/vendor/go.uber.org/zap/example_test.go b/vendor/go.uber.org/zap/example_test.go
new file mode 100644
index 0000000..b61f153
--- /dev/null
+++ b/vendor/go.uber.org/zap/example_test.go
@@ -0,0 +1,327 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap_test
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"log"
+	"os"
+	"time"
+
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+func Example_presets() {
+	// Using zap's preset constructors is the simplest way to get a feel for the
+	// package, but they don't allow much customization.
+	logger := zap.NewExample() // or NewProduction, or NewDevelopment
+	defer logger.Sync()
+
+	const url = "http://example.com"
+
+	// In most circumstances, use the SugaredLogger. It's 4-10x faster than most
+	// other structured logging packages and has a familiar, loosely-typed API.
+	sugar := logger.Sugar()
+	sugar.Infow("Failed to fetch URL.",
+		// Structured context as loosely typed key-value pairs.
+		"url", url,
+		"attempt", 3,
+		"backoff", time.Second,
+	)
+	sugar.Infof("Failed to fetch URL: %s", url)
+
+	// In the unusual situations where every microsecond matters, use the
+	// Logger. It's even faster than the SugaredLogger, but only supports
+	// structured logging.
+	logger.Info("Failed to fetch URL.",
+		// Structured context as strongly typed fields.
+		zap.String("url", url),
+		zap.Int("attempt", 3),
+		zap.Duration("backoff", time.Second),
+	)
+	// Output:
+	// {"level":"info","msg":"Failed to fetch URL.","url":"http://example.com","attempt":3,"backoff":"1s"}
+	// {"level":"info","msg":"Failed to fetch URL: http://example.com"}
+	// {"level":"info","msg":"Failed to fetch URL.","url":"http://example.com","attempt":3,"backoff":"1s"}
+}
+
+func Example_basicConfiguration() {
+	// For some users, the presets offered by the NewProduction, NewDevelopment,
+	// and NewExample constructors won't be appropriate. For most of those
+	// users, the bundled Config struct offers the right balance of flexibility
+	// and convenience. (For more complex needs, see the AdvancedConfiguration
+	// example.)
+	//
+	// See the documentation for Config and zapcore.EncoderConfig for all the
+	// available options.
+	rawJSON := []byte(`{
+	  "level": "debug",
+	  "encoding": "json",
+	  "outputPaths": ["stdout", "/tmp/logs"],
+	  "errorOutputPaths": ["stderr"],
+	  "initialFields": {"foo": "bar"},
+	  "encoderConfig": {
+	    "messageKey": "message",
+	    "levelKey": "level",
+	    "levelEncoder": "lowercase"
+	  }
+	}`)
+
+	var cfg zap.Config
+	if err := json.Unmarshal(rawJSON, &cfg); err != nil {
+		panic(err)
+	}
+	logger, err := cfg.Build()
+	if err != nil {
+		panic(err)
+	}
+	defer logger.Sync()
+
+	logger.Info("logger construction succeeded")
+	// Output:
+	// {"level":"info","message":"logger construction succeeded","foo":"bar"}
+}
+
+func Example_advancedConfiguration() {
+	// The bundled Config struct only supports the most common configuration
+	// options. More complex needs, like splitting logs between multiple files
+	// or writing to non-file outputs, require use of the zapcore package.
+	//
+	// In this example, imagine we're both sending our logs to Kafka and writing
+	// them to the console. We'd like to encode the console output and the Kafka
+	// topics differently, and we'd also like special treatment for
+	// high-priority logs.
+
+	// First, define our level-handling logic.
+	highPriority := zap.LevelEnablerFunc(func(lvl zapcore.Level) bool {
+		return lvl >= zapcore.ErrorLevel
+	})
+	lowPriority := zap.LevelEnablerFunc(func(lvl zapcore.Level) bool {
+		return lvl < zapcore.ErrorLevel
+	})
+
+	// Assume that we have clients for two Kafka topics. The clients implement
+	// zapcore.WriteSyncer and are safe for concurrent use. (If they only
+	// implement io.Writer, we can use zapcore.AddSync to add a no-op Sync
+	// method. If they're not safe for concurrent use, we can add a protecting
+	// mutex with zapcore.Lock.)
+	topicDebugging := zapcore.AddSync(ioutil.Discard)
+	topicErrors := zapcore.AddSync(ioutil.Discard)
+
+	// High-priority output should also go to standard error, and low-priority
+	// output should also go to standard out.
+	consoleDebugging := zapcore.Lock(os.Stdout)
+	consoleErrors := zapcore.Lock(os.Stderr)
+
+	// Optimize the Kafka output for machine consumption and the console output
+	// for human operators.
+	kafkaEncoder := zapcore.NewJSONEncoder(zap.NewProductionEncoderConfig())
+	consoleEncoder := zapcore.NewConsoleEncoder(zap.NewDevelopmentEncoderConfig())
+
+	// Join the outputs, encoders, and level-handling functions into
+	// zapcore.Cores, then tee the four cores together.
+	core := zapcore.NewTee(
+		zapcore.NewCore(kafkaEncoder, topicErrors, highPriority),
+		zapcore.NewCore(consoleEncoder, consoleErrors, highPriority),
+		zapcore.NewCore(kafkaEncoder, topicDebugging, lowPriority),
+		zapcore.NewCore(consoleEncoder, consoleDebugging, lowPriority),
+	)
+
+	// From a zapcore.Core, it's easy to construct a Logger.
+	logger := zap.New(core)
+	defer logger.Sync()
+	logger.Info("constructed a logger")
+}
+
+func ExampleNamespace() {
+	logger := zap.NewExample()
+	defer logger.Sync()
+
+	logger.With(
+		zap.Namespace("metrics"),
+		zap.Int("counter", 1),
+	).Info("tracked some metrics")
+	// Output:
+	// {"level":"info","msg":"tracked some metrics","metrics":{"counter":1}}
+}
+
+func ExampleNewStdLog() {
+	logger := zap.NewExample()
+	defer logger.Sync()
+
+	std := zap.NewStdLog(logger)
+	std.Print("standard logger wrapper")
+	// Output:
+	// {"level":"info","msg":"standard logger wrapper"}
+}
+
+func ExampleRedirectStdLog() {
+	logger := zap.NewExample()
+	defer logger.Sync()
+
+	undo := zap.RedirectStdLog(logger)
+	defer undo()
+
+	log.Print("redirected standard library")
+	// Output:
+	// {"level":"info","msg":"redirected standard library"}
+}
+
+func ExampleReplaceGlobals() {
+	logger := zap.NewExample()
+	defer logger.Sync()
+
+	undo := zap.ReplaceGlobals(logger)
+	defer undo()
+
+	zap.L().Info("replaced zap's global loggers")
+	// Output:
+	// {"level":"info","msg":"replaced zap's global loggers"}
+}
+
+func ExampleAtomicLevel() {
+	atom := zap.NewAtomicLevel()
+
+	// To keep the example deterministic, disable timestamps in the output.
+	encoderCfg := zap.NewProductionEncoderConfig()
+	encoderCfg.TimeKey = ""
+
+	logger := zap.New(zapcore.NewCore(
+		zapcore.NewJSONEncoder(encoderCfg),
+		zapcore.Lock(os.Stdout),
+		atom,
+	))
+	defer logger.Sync()
+
+	logger.Info("info logging enabled")
+
+	atom.SetLevel(zap.ErrorLevel)
+	logger.Info("info logging disabled")
+	// Output:
+	// {"level":"info","msg":"info logging enabled"}
+}
+
+func ExampleAtomicLevel_config() {
+	// The zap.Config struct includes an AtomicLevel. To use it, keep a
+	// reference to the Config.
+	rawJSON := []byte(`{
+		"level": "info",
+		"outputPaths": ["stdout"],
+		"errorOutputPaths": ["stderr"],
+		"encoding": "json",
+		"encoderConfig": {
+			"messageKey": "message",
+			"levelKey": "level",
+			"levelEncoder": "lowercase"
+		}
+	}`)
+	var cfg zap.Config
+	if err := json.Unmarshal(rawJSON, &cfg); err != nil {
+		panic(err)
+	}
+	logger, err := cfg.Build()
+	if err != nil {
+		panic(err)
+	}
+	defer logger.Sync()
+
+	logger.Info("info logging enabled")
+
+	cfg.Level.SetLevel(zap.ErrorLevel)
+	logger.Info("info logging disabled")
+	// Output:
+	// {"level":"info","message":"info logging enabled"}
+}
+
+func ExampleLogger_Check() {
+	logger := zap.NewExample()
+	defer logger.Sync()
+
+	if ce := logger.Check(zap.DebugLevel, "debugging"); ce != nil {
+		// If debug-level log output isn't enabled or if zap's sampling would have
+		// dropped this log entry, we don't allocate the slice that holds these
+		// fields.
+		ce.Write(
+			zap.String("foo", "bar"),
+			zap.String("baz", "quux"),
+		)
+	}
+
+	// Output:
+	// {"level":"debug","msg":"debugging","foo":"bar","baz":"quux"}
+}
+
+func ExampleLogger_Named() {
+	logger := zap.NewExample()
+	defer logger.Sync()
+
+	// By default, Loggers are unnamed.
+	logger.Info("no name")
+
+	// The first call to Named sets the Logger name.
+	main := logger.Named("main")
+	main.Info("main logger")
+
+	// Additional calls to Named create a period-separated path.
+	main.Named("subpackage").Info("sub-logger")
+	// Output:
+	// {"level":"info","msg":"no name"}
+	// {"level":"info","logger":"main","msg":"main logger"}
+	// {"level":"info","logger":"main.subpackage","msg":"sub-logger"}
+}
+
+func ExampleWrapCore_replace() {
+	// Replacing a Logger's core can alter fundamental behaviors. For example,
+	// example, it can convert a Logger to a no-op.
+	nop := zap.WrapCore(func(zapcore.Core) zapcore.Core {
+		return zapcore.NewNopCore()
+	})
+
+	logger := zap.NewExample()
+	defer logger.Sync()
+
+	logger.Info("working")
+	logger.WithOptions(nop).Info("no-op")
+	logger.Info("original logger still works")
+	// Output:
+	// {"level":"info","msg":"working"}
+	// {"level":"info","msg":"original logger still works"}
+}
+
+func ExampleWrapCore_wrap() {
+	// Wrapping a Logger's core can extend its functionality. As a trivial
+	// example, it can double-write all logs.
+	doubled := zap.WrapCore(func(c zapcore.Core) zapcore.Core {
+		return zapcore.NewTee(c, c)
+	})
+
+	logger := zap.NewExample()
+	defer logger.Sync()
+
+	logger.Info("single")
+	logger.WithOptions(doubled).Info("doubled")
+	// Output:
+	// {"level":"info","msg":"single"}
+	// {"level":"info","msg":"doubled"}
+	// {"level":"info","msg":"doubled"}
+}
diff --git a/vendor/go.uber.org/zap/field.go b/vendor/go.uber.org/zap/field.go
new file mode 100644
index 0000000..20eb487
--- /dev/null
+++ b/vendor/go.uber.org/zap/field.go
@@ -0,0 +1,306 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"fmt"
+	"math"
+	"time"
+
+	"go.uber.org/zap/zapcore"
+)
+
+// Skip constructs a no-op field, which is often useful when handling invalid
+// inputs in other Field constructors.
+func Skip() zapcore.Field {
+	return zapcore.Field{Type: zapcore.SkipType}
+}
+
+// Binary constructs a field that carries an opaque binary blob.
+//
+// Binary data is serialized in an encoding-appropriate format. For example,
+// zap's JSON encoder base64-encodes binary blobs. To log UTF-8 encoded text,
+// use ByteString.
+func Binary(key string, val []byte) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.BinaryType, Interface: val}
+}
+
+// Bool constructs a field that carries a bool.
+func Bool(key string, val bool) zapcore.Field {
+	var ival int64
+	if val {
+		ival = 1
+	}
+	return zapcore.Field{Key: key, Type: zapcore.BoolType, Integer: ival}
+}
+
+// ByteString constructs a field that carries UTF-8 encoded text as a []byte.
+// To log opaque binary blobs (which aren't necessarily valid UTF-8), use
+// Binary.
+func ByteString(key string, val []byte) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.ByteStringType, Interface: val}
+}
+
+// Complex128 constructs a field that carries a complex number. Unlike most
+// numeric fields, this costs an allocation (to convert the complex128 to
+// interface{}).
+func Complex128(key string, val complex128) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.Complex128Type, Interface: val}
+}
+
+// Complex64 constructs a field that carries a complex number. Unlike most
+// numeric fields, this costs an allocation (to convert the complex64 to
+// interface{}).
+func Complex64(key string, val complex64) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.Complex64Type, Interface: val}
+}
+
+// Float64 constructs a field that carries a float64. The way the
+// floating-point value is represented is encoder-dependent, so marshaling is
+// necessarily lazy.
+func Float64(key string, val float64) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.Float64Type, Integer: int64(math.Float64bits(val))}
+}
+
+// Float32 constructs a field that carries a float32. The way the
+// floating-point value is represented is encoder-dependent, so marshaling is
+// necessarily lazy.
+func Float32(key string, val float32) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.Float32Type, Integer: int64(math.Float32bits(val))}
+}
+
+// Int constructs a field with the given key and value.
+func Int(key string, val int) zapcore.Field {
+	return Int64(key, int64(val))
+}
+
+// Int64 constructs a field with the given key and value.
+func Int64(key string, val int64) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.Int64Type, Integer: val}
+}
+
+// Int32 constructs a field with the given key and value.
+func Int32(key string, val int32) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.Int32Type, Integer: int64(val)}
+}
+
+// Int16 constructs a field with the given key and value.
+func Int16(key string, val int16) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.Int16Type, Integer: int64(val)}
+}
+
+// Int8 constructs a field with the given key and value.
+func Int8(key string, val int8) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.Int8Type, Integer: int64(val)}
+}
+
+// String constructs a field with the given key and value.
+func String(key string, val string) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.StringType, String: val}
+}
+
+// Uint constructs a field with the given key and value.
+func Uint(key string, val uint) zapcore.Field {
+	return Uint64(key, uint64(val))
+}
+
+// Uint64 constructs a field with the given key and value.
+func Uint64(key string, val uint64) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.Uint64Type, Integer: int64(val)}
+}
+
+// Uint32 constructs a field with the given key and value.
+func Uint32(key string, val uint32) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.Uint32Type, Integer: int64(val)}
+}
+
+// Uint16 constructs a field with the given key and value.
+func Uint16(key string, val uint16) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.Uint16Type, Integer: int64(val)}
+}
+
+// Uint8 constructs a field with the given key and value.
+func Uint8(key string, val uint8) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.Uint8Type, Integer: int64(val)}
+}
+
+// Uintptr constructs a field with the given key and value.
+func Uintptr(key string, val uintptr) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.UintptrType, Integer: int64(val)}
+}
+
+// Reflect constructs a field with the given key and an arbitrary object. It uses
+// an encoding-appropriate, reflection-based function to lazily serialize nearly
+// any object into the logging context, but it's relatively slow and
+// allocation-heavy. Outside tests, Any is always a better choice.
+//
+// If encoding fails (e.g., trying to serialize a map[int]string to JSON), Reflect
+// includes the error message in the final log output.
+func Reflect(key string, val interface{}) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.ReflectType, Interface: val}
+}
+
+// Namespace creates a named, isolated scope within the logger's context. All
+// subsequent fields will be added to the new namespace.
+//
+// This helps prevent key collisions when injecting loggers into sub-components
+// or third-party libraries.
+func Namespace(key string) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.NamespaceType}
+}
+
+// Stringer constructs a field with the given key and the output of the value's
+// String method. The Stringer's String method is called lazily.
+func Stringer(key string, val fmt.Stringer) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.StringerType, Interface: val}
+}
+
+// Time constructs a zapcore.Field with the given key and value. The encoder
+// controls how the time is serialized.
+func Time(key string, val time.Time) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.TimeType, Integer: val.UnixNano(), Interface: val.Location()}
+}
+
+// Stack constructs a field that stores a stacktrace of the current goroutine
+// under provided key. Keep in mind that taking a stacktrace is eager and
+// expensive (relatively speaking); this function both makes an allocation and
+// takes about two microseconds.
+func Stack(key string) zapcore.Field {
+	// Returning the stacktrace as a string costs an allocation, but saves us
+	// from expanding the zapcore.Field union struct to include a byte slice. Since
+	// taking a stacktrace is already so expensive (~10us), the extra allocation
+	// is okay.
+	return String(key, takeStacktrace())
+}
+
+// Duration constructs a field with the given key and value. The encoder
+// controls how the duration is serialized.
+func Duration(key string, val time.Duration) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.DurationType, Integer: int64(val)}
+}
+
+// Object constructs a field with the given key and ObjectMarshaler. It
+// provides a flexible, but still type-safe and efficient, way to add map- or
+// struct-like user-defined types to the logging context. The struct's
+// MarshalLogObject method is called lazily.
+func Object(key string, val zapcore.ObjectMarshaler) zapcore.Field {
+	return zapcore.Field{Key: key, Type: zapcore.ObjectMarshalerType, Interface: val}
+}
+
+// Any takes a key and an arbitrary value and chooses the best way to represent
+// them as a field, falling back to a reflection-based approach only if
+// necessary.
+//
+// Since byte/uint8 and rune/int32 are aliases, Any can't differentiate between
+// them. To minimize suprise, []byte values are treated as binary blobs, byte
+// values are treated as uint8, and runes are always treated as integers.
+func Any(key string, value interface{}) zapcore.Field {
+	switch val := value.(type) {
+	case zapcore.ObjectMarshaler:
+		return Object(key, val)
+	case zapcore.ArrayMarshaler:
+		return Array(key, val)
+	case bool:
+		return Bool(key, val)
+	case []bool:
+		return Bools(key, val)
+	case complex128:
+		return Complex128(key, val)
+	case []complex128:
+		return Complex128s(key, val)
+	case complex64:
+		return Complex64(key, val)
+	case []complex64:
+		return Complex64s(key, val)
+	case float64:
+		return Float64(key, val)
+	case []float64:
+		return Float64s(key, val)
+	case float32:
+		return Float32(key, val)
+	case []float32:
+		return Float32s(key, val)
+	case int:
+		return Int(key, val)
+	case []int:
+		return Ints(key, val)
+	case int64:
+		return Int64(key, val)
+	case []int64:
+		return Int64s(key, val)
+	case int32:
+		return Int32(key, val)
+	case []int32:
+		return Int32s(key, val)
+	case int16:
+		return Int16(key, val)
+	case []int16:
+		return Int16s(key, val)
+	case int8:
+		return Int8(key, val)
+	case []int8:
+		return Int8s(key, val)
+	case string:
+		return String(key, val)
+	case []string:
+		return Strings(key, val)
+	case uint:
+		return Uint(key, val)
+	case []uint:
+		return Uints(key, val)
+	case uint64:
+		return Uint64(key, val)
+	case []uint64:
+		return Uint64s(key, val)
+	case uint32:
+		return Uint32(key, val)
+	case []uint32:
+		return Uint32s(key, val)
+	case uint16:
+		return Uint16(key, val)
+	case []uint16:
+		return Uint16s(key, val)
+	case uint8:
+		return Uint8(key, val)
+	case []byte:
+		return Binary(key, val)
+	case uintptr:
+		return Uintptr(key, val)
+	case []uintptr:
+		return Uintptrs(key, val)
+	case time.Time:
+		return Time(key, val)
+	case []time.Time:
+		return Times(key, val)
+	case time.Duration:
+		return Duration(key, val)
+	case []time.Duration:
+		return Durations(key, val)
+	case error:
+		return NamedError(key, val)
+	case []error:
+		return Errors(key, val)
+	case fmt.Stringer:
+		return Stringer(key, val)
+	default:
+		return Reflect(key, val)
+	}
+}
diff --git a/vendor/go.uber.org/zap/field_test.go b/vendor/go.uber.org/zap/field_test.go
new file mode 100644
index 0000000..c13922c
--- /dev/null
+++ b/vendor/go.uber.org/zap/field_test.go
@@ -0,0 +1,159 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"net"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"go.uber.org/zap/zapcore"
+)
+
+type username string
+
+func (n username) MarshalLogObject(enc zapcore.ObjectEncoder) error {
+	enc.AddString("username", string(n))
+	return nil
+}
+
+func assertCanBeReused(t testing.TB, field zapcore.Field) {
+	var wg sync.WaitGroup
+
+	for i := 0; i < 100; i++ {
+		enc := zapcore.NewMapObjectEncoder()
+
+		// Ensure using the field in multiple encoders in separate goroutines
+		// does not cause any races or panics.
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			assert.NotPanics(t, func() {
+				field.AddTo(enc)
+			}, "Reusing a field should not cause issues")
+		}()
+	}
+
+	wg.Wait()
+}
+
+func TestFieldConstructors(t *testing.T) {
+	// Interface types.
+	addr := net.ParseIP("1.2.3.4")
+	name := username("phil")
+	ints := []int{5, 6}
+
+	tests := []struct {
+		name   string
+		field  zapcore.Field
+		expect zapcore.Field
+	}{
+		{"Skip", zapcore.Field{Type: zapcore.SkipType}, Skip()},
+		{"Binary", zapcore.Field{Key: "k", Type: zapcore.BinaryType, Interface: []byte("ab12")}, Binary("k", []byte("ab12"))},
+		{"Bool", zapcore.Field{Key: "k", Type: zapcore.BoolType, Integer: 1}, Bool("k", true)},
+		{"Bool", zapcore.Field{Key: "k", Type: zapcore.BoolType, Integer: 1}, Bool("k", true)},
+		{"ByteString", zapcore.Field{Key: "k", Type: zapcore.ByteStringType, Interface: []byte("ab12")}, ByteString("k", []byte("ab12"))},
+		{"Complex128", zapcore.Field{Key: "k", Type: zapcore.Complex128Type, Interface: 1 + 2i}, Complex128("k", 1+2i)},
+		{"Complex64", zapcore.Field{Key: "k", Type: zapcore.Complex64Type, Interface: complex64(1 + 2i)}, Complex64("k", 1+2i)},
+		{"Duration", zapcore.Field{Key: "k", Type: zapcore.DurationType, Integer: 1}, Duration("k", 1)},
+		{"Int", zapcore.Field{Key: "k", Type: zapcore.Int64Type, Integer: 1}, Int("k", 1)},
+		{"Int64", zapcore.Field{Key: "k", Type: zapcore.Int64Type, Integer: 1}, Int64("k", 1)},
+		{"Int32", zapcore.Field{Key: "k", Type: zapcore.Int32Type, Integer: 1}, Int32("k", 1)},
+		{"Int16", zapcore.Field{Key: "k", Type: zapcore.Int16Type, Integer: 1}, Int16("k", 1)},
+		{"Int8", zapcore.Field{Key: "k", Type: zapcore.Int8Type, Integer: 1}, Int8("k", 1)},
+		{"String", zapcore.Field{Key: "k", Type: zapcore.StringType, String: "foo"}, String("k", "foo")},
+		{"Time", zapcore.Field{Key: "k", Type: zapcore.TimeType, Integer: 0, Interface: time.UTC}, Time("k", time.Unix(0, 0).In(time.UTC))},
+		{"Time", zapcore.Field{Key: "k", Type: zapcore.TimeType, Integer: 1000, Interface: time.UTC}, Time("k", time.Unix(0, 1000).In(time.UTC))},
+		{"Uint", zapcore.Field{Key: "k", Type: zapcore.Uint64Type, Integer: 1}, Uint("k", 1)},
+		{"Uint64", zapcore.Field{Key: "k", Type: zapcore.Uint64Type, Integer: 1}, Uint64("k", 1)},
+		{"Uint32", zapcore.Field{Key: "k", Type: zapcore.Uint32Type, Integer: 1}, Uint32("k", 1)},
+		{"Uint16", zapcore.Field{Key: "k", Type: zapcore.Uint16Type, Integer: 1}, Uint16("k", 1)},
+		{"Uint8", zapcore.Field{Key: "k", Type: zapcore.Uint8Type, Integer: 1}, Uint8("k", 1)},
+		{"Uintptr", zapcore.Field{Key: "k", Type: zapcore.UintptrType, Integer: 10}, Uintptr("k", 0xa)},
+		{"Reflect", zapcore.Field{Key: "k", Type: zapcore.ReflectType, Interface: ints}, Reflect("k", ints)},
+		{"Stringer", zapcore.Field{Key: "k", Type: zapcore.StringerType, Interface: addr}, Stringer("k", addr)},
+		{"Object", zapcore.Field{Key: "k", Type: zapcore.ObjectMarshalerType, Interface: name}, Object("k", name)},
+		{"Any:ObjectMarshaler", Any("k", name), Object("k", name)},
+		{"Any:ArrayMarshaler", Any("k", bools([]bool{true})), Array("k", bools([]bool{true}))},
+		{"Any:Stringer", Any("k", addr), Stringer("k", addr)},
+		{"Any:Bool", Any("k", true), Bool("k", true)},
+		{"Any:Bools", Any("k", []bool{true}), Bools("k", []bool{true})},
+		{"Any:Byte", Any("k", byte(1)), Uint8("k", 1)},
+		{"Any:Bytes", Any("k", []byte{1}), Binary("k", []byte{1})},
+		{"Any:Complex128", Any("k", 1+2i), Complex128("k", 1+2i)},
+		{"Any:Complex128s", Any("k", []complex128{1 + 2i}), Complex128s("k", []complex128{1 + 2i})},
+		{"Any:Complex64", Any("k", complex64(1+2i)), Complex64("k", 1+2i)},
+		{"Any:Complex64s", Any("k", []complex64{1 + 2i}), Complex64s("k", []complex64{1 + 2i})},
+		{"Any:Float64", Any("k", 3.14), Float64("k", 3.14)},
+		{"Any:Float64s", Any("k", []float64{3.14}), Float64s("k", []float64{3.14})},
+		{"Any:Float32", Any("k", float32(3.14)), Float32("k", 3.14)},
+		{"Any:Float32s", Any("k", []float32{3.14}), Float32s("k", []float32{3.14})},
+		{"Any:Int", Any("k", 1), Int("k", 1)},
+		{"Any:Ints", Any("k", []int{1}), Ints("k", []int{1})},
+		{"Any:Int64", Any("k", int64(1)), Int64("k", 1)},
+		{"Any:Int64s", Any("k", []int64{1}), Int64s("k", []int64{1})},
+		{"Any:Int32", Any("k", int32(1)), Int32("k", 1)},
+		{"Any:Int32s", Any("k", []int32{1}), Int32s("k", []int32{1})},
+		{"Any:Int16", Any("k", int16(1)), Int16("k", 1)},
+		{"Any:Int16s", Any("k", []int16{1}), Int16s("k", []int16{1})},
+		{"Any:Int8", Any("k", int8(1)), Int8("k", 1)},
+		{"Any:Int8s", Any("k", []int8{1}), Int8s("k", []int8{1})},
+		{"Any:Rune", Any("k", rune(1)), Int32("k", 1)},
+		{"Any:Runes", Any("k", []rune{1}), Int32s("k", []int32{1})},
+		{"Any:String", Any("k", "v"), String("k", "v")},
+		{"Any:Strings", Any("k", []string{"v"}), Strings("k", []string{"v"})},
+		{"Any:Uint", Any("k", uint(1)), Uint("k", 1)},
+		{"Any:Uints", Any("k", []uint{1}), Uints("k", []uint{1})},
+		{"Any:Uint64", Any("k", uint64(1)), Uint64("k", 1)},
+		{"Any:Uint64s", Any("k", []uint64{1}), Uint64s("k", []uint64{1})},
+		{"Any:Uint32", Any("k", uint32(1)), Uint32("k", 1)},
+		{"Any:Uint32s", Any("k", []uint32{1}), Uint32s("k", []uint32{1})},
+		{"Any:Uint16", Any("k", uint16(1)), Uint16("k", 1)},
+		{"Any:Uint16s", Any("k", []uint16{1}), Uint16s("k", []uint16{1})},
+		{"Any:Uint8", Any("k", uint8(1)), Uint8("k", 1)},
+		{"Any:Uint8s", Any("k", []uint8{1}), Binary("k", []uint8{1})},
+		{"Any:Uintptr", Any("k", uintptr(1)), Uintptr("k", 1)},
+		{"Any:Uintptrs", Any("k", []uintptr{1}), Uintptrs("k", []uintptr{1})},
+		{"Any:Time", Any("k", time.Unix(0, 0)), Time("k", time.Unix(0, 0))},
+		{"Any:Times", Any("k", []time.Time{time.Unix(0, 0)}), Times("k", []time.Time{time.Unix(0, 0)})},
+		{"Any:Duration", Any("k", time.Second), Duration("k", time.Second)},
+		{"Any:Durations", Any("k", []time.Duration{time.Second}), Durations("k", []time.Duration{time.Second})},
+		{"Any:Fallback", Any("k", struct{}{}), Reflect("k", struct{}{})},
+		{"Namespace", Namespace("k"), zapcore.Field{Key: "k", Type: zapcore.NamespaceType}},
+	}
+
+	for _, tt := range tests {
+		if !assert.Equal(t, tt.expect, tt.field, "Unexpected output from convenience field constructor %s.", tt.name) {
+			t.Logf("type expected: %T\nGot: %T", tt.expect.Interface, tt.field.Interface)
+		}
+		assertCanBeReused(t, tt.field)
+	}
+}
+
+func TestStackField(t *testing.T) {
+	f := Stack("stacktrace")
+	assert.Equal(t, "stacktrace", f.Key, "Unexpected field key.")
+	assert.Equal(t, zapcore.StringType, f.Type, "Unexpected field type.")
+	assert.Equal(t, takeStacktrace(), f.String, "Unexpected stack trace")
+	assertCanBeReused(t, f)
+}
diff --git a/vendor/go.uber.org/zap/flag.go b/vendor/go.uber.org/zap/flag.go
new file mode 100644
index 0000000..1312875
--- /dev/null
+++ b/vendor/go.uber.org/zap/flag.go
@@ -0,0 +1,39 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"flag"
+
+	"go.uber.org/zap/zapcore"
+)
+
+// LevelFlag uses the standard library's flag.Var to declare a global flag
+// with the specified name, default, and usage guidance. The returned value is
+// a pointer to the value of the flag.
+//
+// If you don't want to use the flag package's global state, you can use any
+// non-nil *Level as a flag.Value with your own *flag.FlagSet.
+func LevelFlag(name string, defaultLevel zapcore.Level, usage string) *zapcore.Level {
+	lvl := defaultLevel
+	flag.Var(&lvl, name, usage)
+	return &lvl
+}
diff --git a/vendor/go.uber.org/zap/flag_test.go b/vendor/go.uber.org/zap/flag_test.go
new file mode 100644
index 0000000..b169894
--- /dev/null
+++ b/vendor/go.uber.org/zap/flag_test.go
@@ -0,0 +1,102 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"flag"
+	"io/ioutil"
+	"testing"
+
+	"go.uber.org/zap/zapcore"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type flagTestCase struct {
+	args      []string
+	wantLevel zapcore.Level
+	wantErr   bool
+}
+
+func (tc flagTestCase) runImplicitSet(t testing.TB) {
+	origCommandLine := flag.CommandLine
+	flag.CommandLine = flag.NewFlagSet("test", flag.ContinueOnError)
+	flag.CommandLine.SetOutput(ioutil.Discard)
+	defer func() { flag.CommandLine = origCommandLine }()
+
+	level := LevelFlag("level", InfoLevel, "")
+	tc.run(t, flag.CommandLine, level)
+}
+
+func (tc flagTestCase) runExplicitSet(t testing.TB) {
+	var lvl zapcore.Level
+	set := flag.NewFlagSet("test", flag.ContinueOnError)
+	set.Var(&lvl, "level", "minimum enabled logging level")
+	tc.run(t, set, &lvl)
+}
+
+func (tc flagTestCase) run(t testing.TB, set *flag.FlagSet, actual *zapcore.Level) {
+	err := set.Parse(tc.args)
+	if tc.wantErr {
+		assert.Error(t, err, "Parse(%v) should fail.", tc.args)
+		return
+	}
+	if assert.NoError(t, err, "Parse(%v) should succeed.", tc.args) {
+		assert.Equal(t, tc.wantLevel, *actual, "Level mismatch.")
+	}
+}
+
+func TestLevelFlag(t *testing.T) {
+	tests := []flagTestCase{
+		{
+			args:      nil,
+			wantLevel: zapcore.InfoLevel,
+		},
+		{
+			args:    []string{"--level", "unknown"},
+			wantErr: true,
+		},
+		{
+			args:      []string{"--level", "error"},
+			wantLevel: zapcore.ErrorLevel,
+		},
+	}
+
+	for _, tt := range tests {
+		tt.runExplicitSet(t)
+		tt.runImplicitSet(t)
+	}
+}
+
+func TestLevelFlagsAreIndependent(t *testing.T) {
+	origCommandLine := flag.CommandLine
+	flag.CommandLine = flag.NewFlagSet("test", flag.ContinueOnError)
+	flag.CommandLine.SetOutput(ioutil.Discard)
+	defer func() { flag.CommandLine = origCommandLine }()
+
+	// Make sure that these two flags are independent.
+	fileLevel := LevelFlag("file-level", InfoLevel, "")
+	consoleLevel := LevelFlag("console-level", InfoLevel, "")
+
+	assert.NoError(t, flag.CommandLine.Parse([]string{"-file-level", "debug"}), "Unexpected flag-parsing error.")
+	assert.Equal(t, InfoLevel, *consoleLevel, "Expected file logging level to remain unchanged.")
+	assert.Equal(t, DebugLevel, *fileLevel, "Expected console logging level to have changed.")
+}
diff --git a/vendor/go.uber.org/zap/glide.lock b/vendor/go.uber.org/zap/glide.lock
new file mode 100644
index 0000000..881b462
--- /dev/null
+++ b/vendor/go.uber.org/zap/glide.lock
@@ -0,0 +1,76 @@
+hash: f073ba522c06c88ea3075bde32a8aaf0969a840a66cab6318a0897d141ffee92
+updated: 2017-07-22T18:06:49.598185334-07:00
+imports:
+- name: go.uber.org/atomic
+  version: 4e336646b2ef9fc6e47be8e21594178f98e5ebcf
+- name: go.uber.org/multierr
+  version: 3c4937480c32f4c13a875a1829af76c98ca3d40a
+testImports:
+- name: github.com/apex/log
+  version: d9b960447bfa720077b2da653cc79e533455b499
+  subpackages:
+  - handlers/json
+- name: github.com/axw/gocov
+  version: 3a69a0d2a4ef1f263e2d92b041a69593d6964fe8
+  subpackages:
+  - gocov
+- name: github.com/davecgh/go-spew
+  version: 04cdfd42973bb9c8589fd6a731800cf222fde1a9
+  subpackages:
+  - spew
+- name: github.com/fatih/color
+  version: 62e9147c64a1ed519147b62a56a14e83e2be02c1
+- name: github.com/go-kit/kit
+  version: e10f5bf035be9af21fd5b2fb4469d5716c6ab07d
+  subpackages:
+  - log
+- name: github.com/go-logfmt/logfmt
+  version: 390ab7935ee28ec6b286364bba9b4dd6410cb3d5
+- name: github.com/go-stack/stack
+  version: 54be5f394ed2c3e19dac9134a40a95ba5a017f7b
+- name: github.com/golang/lint
+  version: c5fb716d6688a859aae56d26d3e6070808df29f7
+  subpackages:
+  - golint
+- name: github.com/kr/logfmt
+  version: b84e30acd515aadc4b783ad4ff83aff3299bdfe0
+- name: github.com/mattn/go-colorable
+  version: 3fa8c76f9daed4067e4a806fb7e4dc86455c6d6a
+- name: github.com/mattn/go-isatty
+  version: fc9e8d8ef48496124e79ae0df75490096eccf6fe
+- name: github.com/mattn/goveralls
+  version: 6efce81852ad1b7567c17ad71b03aeccc9dd9ae0
+- name: github.com/pborman/uuid
+  version: e790cca94e6cc75c7064b1332e63811d4aae1a53
+- name: github.com/pkg/errors
+  version: 645ef00459ed84a119197bfb8d8205042c6df63d
+- name: github.com/pmezard/go-difflib
+  version: d8ed2627bdf02c080bf22230dbb337003b7aba2d
+  subpackages:
+  - difflib
+- name: github.com/rs/zerolog
+  version: eed4c2b94d945e0b2456ad6aa518a443986b5f22
+- name: github.com/satori/go.uuid
+  version: 5bf94b69c6b68ee1b541973bb8e1144db23a194b
+- name: github.com/sirupsen/logrus
+  version: 7dd06bf38e1e13df288d471a57d5adbac106be9e
+- name: github.com/stretchr/testify
+  version: f6abca593680b2315d2075e0f5e2a9751e3f431a
+  subpackages:
+  - assert
+  - require
+- name: go.pedge.io/lion
+  version: 87958e8713f1fa138d993087133b97e976642159
+- name: golang.org/x/sys
+  version: c4489faa6e5ab84c0ef40d6ee878f7a030281f0f
+  subpackages:
+  - unix
+- name: golang.org/x/tools
+  version: 496819729719f9d07692195e0a94d6edd2251389
+  subpackages:
+  - cover
+- name: gopkg.in/inconshreveable/log15.v2
+  version: b105bd37f74e5d9dc7b6ad7806715c7a2b83fd3f
+  subpackages:
+  - stack
+  - term
diff --git a/vendor/go.uber.org/zap/glide.yaml b/vendor/go.uber.org/zap/glide.yaml
new file mode 100644
index 0000000..9441259
--- /dev/null
+++ b/vendor/go.uber.org/zap/glide.yaml
@@ -0,0 +1,35 @@
+package: go.uber.org/zap
+license: MIT
+import:
+- package: go.uber.org/atomic
+  version: ^1
+- package: go.uber.org/multierr
+  version: ^1
+testImport:
+- package: github.com/satori/go.uuid
+- package: github.com/sirupsen/logrus
+- package: github.com/apex/log
+  subpackages:
+  - handlers/json
+- package: github.com/go-kit/kit
+  subpackages:
+  - log
+- package: github.com/stretchr/testify
+  subpackages:
+  - assert
+  - require
+- package: gopkg.in/inconshreveable/log15.v2
+- package: github.com/mattn/goveralls
+- package: github.com/pborman/uuid
+- package: github.com/pkg/errors
+- package: go.pedge.io/lion
+- package: github.com/rs/zerolog
+- package: golang.org/x/tools
+  subpackages:
+  - cover
+- package: github.com/golang/lint
+  subpackages:
+  - golint
+- package: github.com/axw/gocov
+  subpackages:
+  - gocov
diff --git a/vendor/go.uber.org/zap/global.go b/vendor/go.uber.org/zap/global.go
new file mode 100644
index 0000000..d345455
--- /dev/null
+++ b/vendor/go.uber.org/zap/global.go
@@ -0,0 +1,139 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+	"os"
+	"sync"
+
+	"go.uber.org/zap/zapcore"
+)
+
+const (
+	_stdLogDefaultDepth = 2
+	_loggerWriterDepth  = 2
+)
+
+var (
+	_globalMu sync.RWMutex
+	_globalL  = NewNop()
+	_globalS  = _globalL.Sugar()
+)
+
+// L returns the global Logger, which can be reconfigured with ReplaceGlobals.
+// It's safe for concurrent use.
+func L() *Logger {
+	_globalMu.RLock()
+	l := _globalL
+	_globalMu.RUnlock()
+	return l
+}
+
+// S returns the global SugaredLogger, which can be reconfigured with
+// ReplaceGlobals. It's safe for concurrent use.
+func S() *SugaredLogger {
+	_globalMu.RLock()
+	s := _globalS
+	_globalMu.RUnlock()
+	return s
+}
+
+// ReplaceGlobals replaces the global Logger and SugaredLogger, and returns a
+// function to restore the original values. It's safe for concurrent use.
+func ReplaceGlobals(logger *Logger) func() {
+	_globalMu.Lock()
+	prev := _globalL
+	_globalL = logger
+	_globalS = logger.Sugar()
+	_globalMu.Unlock()
+	return func() { ReplaceGlobals(prev) }
+}
+
+// NewStdLog returns a *log.Logger which writes to the supplied zap Logger at
+// InfoLevel. To redirect the standard library's package-global logging
+// functions, use RedirectStdLog instead.
+func NewStdLog(l *Logger) *log.Logger {
+	logger := l.WithOptions(AddCallerSkip(_stdLogDefaultDepth + _loggerWriterDepth))
+	f := logger.Info
+	return log.New(&loggerWriter{f}, "" /* prefix */, 0 /* flags */)
+}
+
+// NewStdLogAt returns *log.Logger which writes to supplied zap logger at
+// required level.
+func NewStdLogAt(l *Logger, level zapcore.Level) (*log.Logger, error) {
+	logger := l.WithOptions(AddCallerSkip(_stdLogDefaultDepth + _loggerWriterDepth))
+	var logFunc func(string, ...zapcore.Field)
+	switch level {
+	case DebugLevel:
+		logFunc = logger.Debug
+	case InfoLevel:
+		logFunc = logger.Info
+	case WarnLevel:
+		logFunc = logger.Warn
+	case ErrorLevel:
+		logFunc = logger.Error
+	case DPanicLevel:
+		logFunc = logger.DPanic
+	case PanicLevel:
+		logFunc = logger.Panic
+	case FatalLevel:
+		logFunc = logger.Fatal
+	default:
+		return nil, fmt.Errorf("unrecognized level: %q", level)
+	}
+	return log.New(&loggerWriter{logFunc}, "" /* prefix */, 0 /* flags */), nil
+}
+
+// RedirectStdLog redirects output from the standard library's package-global
+// logger to the supplied logger at InfoLevel. Since zap already handles caller
+// annotations, timestamps, etc., it automatically disables the standard
+// library's annotations and prefixing.
+//
+// It returns a function to restore the original prefix and flags and reset the
+// standard library's output to os.Stdout.
+func RedirectStdLog(l *Logger) func() {
+	flags := log.Flags()
+	prefix := log.Prefix()
+	log.SetFlags(0)
+	log.SetPrefix("")
+	logFunc := l.WithOptions(
+		AddCallerSkip(_stdLogDefaultDepth + _loggerWriterDepth),
+	).Info
+	log.SetOutput(&loggerWriter{logFunc})
+	return func() {
+		log.SetFlags(flags)
+		log.SetPrefix(prefix)
+		log.SetOutput(os.Stderr)
+	}
+}
+
+type loggerWriter struct {
+	logFunc func(msg string, fields ...zapcore.Field)
+}
+
+func (l *loggerWriter) Write(p []byte) (int, error) {
+	p = bytes.TrimSpace(p)
+	l.logFunc(string(p))
+	return len(p), nil
+}
diff --git a/vendor/go.uber.org/zap/global_test.go b/vendor/go.uber.org/zap/global_test.go
new file mode 100644
index 0000000..7da3b94
--- /dev/null
+++ b/vendor/go.uber.org/zap/global_test.go
@@ -0,0 +1,189 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"log"
+	"sync"
+	"testing"
+	"time"
+
+	"go.uber.org/zap/internal/exit"
+
+	"go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest"
+	"go.uber.org/zap/zaptest/observer"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/atomic"
+)
+
+func TestReplaceGlobals(t *testing.T) {
+	initialL := *L()
+	initialS := *S()
+
+	withLogger(t, DebugLevel, nil, func(l *Logger, logs *observer.ObservedLogs) {
+		L().Info("no-op")
+		S().Info("no-op")
+		assert.Equal(t, 0, logs.Len(), "Expected initial logs to go to default no-op global.")
+
+		defer ReplaceGlobals(l)()
+
+		L().Info("captured")
+		S().Info("captured")
+		expected := observer.LoggedEntry{
+			Entry:   zapcore.Entry{Message: "captured"},
+			Context: []zapcore.Field{},
+		}
+		assert.Equal(
+			t,
+			[]observer.LoggedEntry{expected, expected},
+			logs.AllUntimed(),
+			"Unexpected global log output.",
+		)
+	})
+
+	assert.Equal(t, initialL, *L(), "Expected func returned from ReplaceGlobals to restore initial L.")
+	assert.Equal(t, initialS, *S(), "Expected func returned from ReplaceGlobals to restore initial S.")
+}
+
+func TestGlobalsConcurrentUse(t *testing.T) {
+	var (
+		stop atomic.Bool
+		wg   sync.WaitGroup
+	)
+
+	for i := 0; i < 100; i++ {
+		wg.Add(2)
+		go func() {
+			for !stop.Load() {
+				ReplaceGlobals(NewNop())
+			}
+			wg.Done()
+		}()
+		go func() {
+			for !stop.Load() {
+				L().With(Int("foo", 42)).Named("main").WithOptions(Development()).Info("")
+				S().Info("")
+			}
+			wg.Done()
+		}()
+	}
+
+	zaptest.Sleep(100 * time.Millisecond)
+	stop.Toggle()
+	wg.Wait()
+}
+
+func TestNewStdLog(t *testing.T) {
+	withLogger(t, DebugLevel, []Option{AddCaller()}, func(l *Logger, logs *observer.ObservedLogs) {
+		std := NewStdLog(l)
+		std.Print("redirected")
+		checkStdLogMessage(t, "redirected", logs)
+	})
+}
+
+func TestNewStdLogAt(t *testing.T) {
+	// include DPanicLevel here, but do not include Development in options
+	levels := []zapcore.Level{DebugLevel, InfoLevel, WarnLevel, ErrorLevel, DPanicLevel}
+	for _, level := range levels {
+		withLogger(t, DebugLevel, []Option{AddCaller()}, func(l *Logger, logs *observer.ObservedLogs) {
+			std, err := NewStdLogAt(l, level)
+			require.NoError(t, err, "Unexpected error.")
+			std.Print("redirected")
+			checkStdLogMessage(t, "redirected", logs)
+		})
+	}
+}
+
+func TestNewStdLogAtPanics(t *testing.T) {
+	// include DPanicLevel here and enable Development in options
+	levels := []zapcore.Level{DPanicLevel, PanicLevel}
+	for _, level := range levels {
+		withLogger(t, DebugLevel, []Option{AddCaller(), Development()}, func(l *Logger, logs *observer.ObservedLogs) {
+			std, err := NewStdLogAt(l, level)
+			require.NoError(t, err, "Unexpected error")
+			assert.Panics(t, func() { std.Print("redirected") }, "Expected log to panic.")
+			checkStdLogMessage(t, "redirected", logs)
+		})
+	}
+}
+
+func TestNewStdLogAtFatal(t *testing.T) {
+	withLogger(t, DebugLevel, []Option{AddCaller()}, func(l *Logger, logs *observer.ObservedLogs) {
+		stub := exit.WithStub(func() {
+			std, err := NewStdLogAt(l, FatalLevel)
+			require.NoError(t, err, "Unexpected error.")
+			std.Print("redirected")
+			checkStdLogMessage(t, "redirected", logs)
+		})
+		assert.True(t, true, stub.Exited, "Expected Fatal logger call to terminate process.")
+		stub.Unstub()
+	})
+}
+
+func TestNewStdLogAtInvalid(t *testing.T) {
+	_, err := NewStdLogAt(NewNop(), zapcore.Level(99))
+	assert.Error(t, err, "Expected to get error.")
+	assert.Contains(t, err.Error(), "99", "Expected level code in error message")
+}
+
+func TestRedirectStdLog(t *testing.T) {
+	initialFlags := log.Flags()
+	initialPrefix := log.Prefix()
+
+	withLogger(t, DebugLevel, nil, func(l *Logger, logs *observer.ObservedLogs) {
+		defer RedirectStdLog(l)()
+		log.Print("redirected")
+
+		assert.Equal(t, []observer.LoggedEntry{{
+			Entry:   zapcore.Entry{Message: "redirected"},
+			Context: []zapcore.Field{},
+		}}, logs.AllUntimed(), "Unexpected global log output.")
+	})
+
+	assert.Equal(t, initialFlags, log.Flags(), "Expected to reset initial flags.")
+	assert.Equal(t, initialPrefix, log.Prefix(), "Expected to reset initial prefix.")
+}
+
+func TestRedirectStdLogCaller(t *testing.T) {
+	withLogger(t, DebugLevel, []Option{AddCaller()}, func(l *Logger, logs *observer.ObservedLogs) {
+		defer RedirectStdLog(l)()
+		log.Print("redirected")
+		entries := logs.All()
+		require.Len(t, entries, 1, "Unexpected number of logs.")
+		assert.Contains(t, entries[0].Entry.Caller.File, "global_test.go", "Unexpected caller annotation.")
+	})
+}
+
+func checkStdLogMessage(t *testing.T, msg string, logs *observer.ObservedLogs) {
+	require.Equal(t, 1, logs.Len(), "Expected exactly one entry to be logged")
+	entry := logs.AllUntimed()[0]
+	assert.Equal(t, []zapcore.Field{}, entry.Context, "Unexpected entry context.")
+	assert.Equal(t, "redirected", entry.Entry.Message, "Unexpected entry message.")
+	assert.Regexp(
+		t,
+		`go.uber.org/zap/global_test.go:\d+$`,
+		entry.Entry.Caller.String(),
+		"Unexpected caller annotation.",
+	)
+}
diff --git a/vendor/go.uber.org/zap/http_handler.go b/vendor/go.uber.org/zap/http_handler.go
new file mode 100644
index 0000000..f171c38
--- /dev/null
+++ b/vendor/go.uber.org/zap/http_handler.go
@@ -0,0 +1,81 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"go.uber.org/zap/zapcore"
+)
+
+// ServeHTTP is a simple JSON endpoint that can report on or change the current
+// logging level.
+//
+// GET requests return a JSON description of the current logging level. PUT
+// requests change the logging level and expect a payload like:
+//   {"level":"info"}
+//
+// It's perfectly safe to change the logging level while a program is running.
+func (lvl AtomicLevel) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	type errorResponse struct {
+		Error string `json:"error"`
+	}
+	type payload struct {
+		Level *zapcore.Level `json:"level"`
+	}
+
+	enc := json.NewEncoder(w)
+
+	switch r.Method {
+
+	case "GET":
+		current := lvl.Level()
+		enc.Encode(payload{Level: &current})
+
+	case "PUT":
+		var req payload
+
+		if errmess := func() string {
+			if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+				return fmt.Sprintf("Request body must be well-formed JSON: %v", err)
+			}
+			if req.Level == nil {
+				return "Must specify a logging level."
+			}
+			return ""
+		}(); errmess != "" {
+			w.WriteHeader(http.StatusBadRequest)
+			enc.Encode(errorResponse{Error: errmess})
+			return
+		}
+
+		lvl.SetLevel(*req.Level)
+		enc.Encode(req)
+
+	default:
+		w.WriteHeader(http.StatusMethodNotAllowed)
+		enc.Encode(errorResponse{
+			Error: "Only GET and PUT are supported.",
+		})
+	}
+}
diff --git a/vendor/go.uber.org/zap/http_handler_test.go b/vendor/go.uber.org/zap/http_handler_test.go
new file mode 100644
index 0000000..474b3c7
--- /dev/null
+++ b/vendor/go.uber.org/zap/http_handler_test.go
@@ -0,0 +1,131 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap_test
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	. "go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func newHandler() (AtomicLevel, *Logger) {
+	lvl := NewAtomicLevel()
+	logger := New(zapcore.NewNopCore())
+	return lvl, logger
+}
+
+func assertCodeOK(t testing.TB, code int) {
+	assert.Equal(t, http.StatusOK, code, "Unexpected response status code.")
+}
+
+func assertCodeBadRequest(t testing.TB, code int) {
+	assert.Equal(t, http.StatusBadRequest, code, "Unexpected response status code.")
+}
+
+func assertCodeMethodNotAllowed(t testing.TB, code int) {
+	assert.Equal(t, http.StatusMethodNotAllowed, code, "Unexpected response status code.")
+}
+
+func assertResponse(t testing.TB, expectedLevel zapcore.Level, actualBody string) {
+	assert.Equal(t, fmt.Sprintf(`{"level":"%s"}`, expectedLevel)+"\n", actualBody, "Unexpected response body.")
+}
+
+func assertJSONError(t testing.TB, body string) {
+	// Don't need to test exact error message, but one should be present.
+	var payload map[string]interface{}
+	require.NoError(t, json.Unmarshal([]byte(body), &payload), "Expected error response to be JSON.")
+
+	msg, ok := payload["error"]
+	require.True(t, ok, "Error message is an unexpected type.")
+	assert.NotEqual(t, "", msg, "Expected an error message in response.")
+}
+
+func makeRequest(t testing.TB, method string, handler http.Handler, reader io.Reader) (int, string) {
+	ts := httptest.NewServer(handler)
+	defer ts.Close()
+
+	req, err := http.NewRequest(method, ts.URL, reader)
+	require.NoError(t, err, "Error constructing %s request.", method)
+
+	res, err := http.DefaultClient.Do(req)
+	require.NoError(t, err, "Error making %s request.", method)
+	defer res.Body.Close()
+
+	body, err := ioutil.ReadAll(res.Body)
+	require.NoError(t, err, "Error reading request body.")
+
+	return res.StatusCode, string(body)
+}
+
+func TestHTTPHandlerGetLevel(t *testing.T) {
+	lvl, _ := newHandler()
+	code, body := makeRequest(t, "GET", lvl, nil)
+	assertCodeOK(t, code)
+	assertResponse(t, lvl.Level(), body)
+}
+
+func TestHTTPHandlerPutLevel(t *testing.T) {
+	lvl, _ := newHandler()
+
+	code, body := makeRequest(t, "PUT", lvl, strings.NewReader(`{"level":"warn"}`))
+
+	assertCodeOK(t, code)
+	assertResponse(t, lvl.Level(), body)
+}
+
+func TestHTTPHandlerPutUnrecognizedLevel(t *testing.T) {
+	lvl, _ := newHandler()
+	code, body := makeRequest(t, "PUT", lvl, strings.NewReader(`{"level":"unrecognized-level"}`))
+	assertCodeBadRequest(t, code)
+	assertJSONError(t, body)
+}
+
+func TestHTTPHandlerNotJSON(t *testing.T) {
+	lvl, _ := newHandler()
+	code, body := makeRequest(t, "PUT", lvl, strings.NewReader(`{`))
+	assertCodeBadRequest(t, code)
+	assertJSONError(t, body)
+}
+
+func TestHTTPHandlerNoLevelSpecified(t *testing.T) {
+	lvl, _ := newHandler()
+	code, body := makeRequest(t, "PUT", lvl, strings.NewReader(`{}`))
+	assertCodeBadRequest(t, code)
+	assertJSONError(t, body)
+}
+
+func TestHTTPHandlerMethodNotAllowed(t *testing.T) {
+	lvl, _ := newHandler()
+	code, body := makeRequest(t, "POST", lvl, strings.NewReader(`{`))
+	assertCodeMethodNotAllowed(t, code)
+	assertJSONError(t, body)
+}
diff --git a/vendor/go.uber.org/zap/internal/bufferpool/bufferpool.go b/vendor/go.uber.org/zap/internal/bufferpool/bufferpool.go
new file mode 100644
index 0000000..dad583a
--- /dev/null
+++ b/vendor/go.uber.org/zap/internal/bufferpool/bufferpool.go
@@ -0,0 +1,31 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Package bufferpool houses zap's shared internal buffer pool. Third-party
+// packages can recreate the same functionality with buffers.NewPool.
+package bufferpool
+
+import "go.uber.org/zap/buffer"
+
+var (
+	_pool = buffer.NewPool()
+	// Get retrieves a buffer from the pool, creating one if necessary.
+	Get = _pool.Get
+)
diff --git a/vendor/go.uber.org/zap/internal/color/color.go b/vendor/go.uber.org/zap/internal/color/color.go
new file mode 100644
index 0000000..c4d5d02
--- /dev/null
+++ b/vendor/go.uber.org/zap/internal/color/color.go
@@ -0,0 +1,44 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Package color adds coloring functionality for TTY output.
+package color
+
+import "fmt"
+
+// Foreground colors.
+const (
+	Black Color = iota + 30
+	Red
+	Green
+	Yellow
+	Blue
+	Magenta
+	Cyan
+	White
+)
+
+// Color represents a text color.
+type Color uint8
+
+// Add adds the coloring to the given string.
+func (c Color) Add(s string) string {
+	return fmt.Sprintf("\x1b[%dm%s\x1b[0m", uint8(c), s)
+}
diff --git a/vendor/go.uber.org/zap/internal/color/color_test.go b/vendor/go.uber.org/zap/internal/color/color_test.go
new file mode 100644
index 0000000..4982903
--- /dev/null
+++ b/vendor/go.uber.org/zap/internal/color/color_test.go
@@ -0,0 +1,36 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package color
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestColorFormatting(t *testing.T) {
+	assert.Equal(
+		t,
+		"\x1b[31mfoo\x1b[0m",
+		Red.Add("foo"),
+		"Unexpected colored output.",
+	)
+}
diff --git a/vendor/go.uber.org/zap/internal/exit/exit.go b/vendor/go.uber.org/zap/internal/exit/exit.go
new file mode 100644
index 0000000..dfc5b05
--- /dev/null
+++ b/vendor/go.uber.org/zap/internal/exit/exit.go
@@ -0,0 +1,64 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Package exit provides stubs so that unit tests can exercise code that calls
+// os.Exit(1).
+package exit
+
+import "os"
+
+var real = func() { os.Exit(1) }
+
+// Exit normally terminates the process by calling os.Exit(1). If the package
+// is stubbed, it instead records a call in the testing spy.
+func Exit() {
+	real()
+}
+
+// A StubbedExit is a testing fake for os.Exit.
+type StubbedExit struct {
+	Exited bool
+	prev   func()
+}
+
+// Stub substitutes a fake for the call to os.Exit(1).
+func Stub() *StubbedExit {
+	s := &StubbedExit{prev: real}
+	real = s.exit
+	return s
+}
+
+// WithStub runs the supplied function with Exit stubbed. It returns the stub
+// used, so that users can test whether the process would have crashed.
+func WithStub(f func()) *StubbedExit {
+	s := Stub()
+	defer s.Unstub()
+	f()
+	return s
+}
+
+// Unstub restores the previous exit function.
+func (se *StubbedExit) Unstub() {
+	real = se.prev
+}
+
+func (se *StubbedExit) exit() {
+	se.Exited = true
+}
diff --git a/vendor/go.uber.org/zap/internal/exit/exit_test.go b/vendor/go.uber.org/zap/internal/exit/exit_test.go
new file mode 100644
index 0000000..300cdc3
--- /dev/null
+++ b/vendor/go.uber.org/zap/internal/exit/exit_test.go
@@ -0,0 +1,42 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package exit
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestStub(t *testing.T) {
+	tests := []struct {
+		f    func()
+		want bool
+	}{
+		{Exit, true},
+		{func() {}, false},
+	}
+
+	for _, tt := range tests {
+		s := WithStub(tt.f)
+		assert.Equal(t, tt.want, s.Exited, "Stub captured unexpected exit value.")
+	}
+}
diff --git a/vendor/go.uber.org/zap/internal/readme/readme.go b/vendor/go.uber.org/zap/internal/readme/readme.go
new file mode 100644
index 0000000..903a4e1
--- /dev/null
+++ b/vendor/go.uber.org/zap/internal/readme/readme.go
@@ -0,0 +1,212 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"os/exec"
+	"sort"
+	"strconv"
+	"strings"
+	"text/template"
+	"time"
+)
+
+var (
+	libraryNameToMarkdownName = map[string]string{
+		"Zap":                   ":zap: zap",
+		"Zap.Sugar":             ":zap: zap (sugared)",
+		"stdlib.Println":        "standard library",
+		"sirupsen/logrus":       "logrus",
+		"go-kit/kit/log":        "go-kit",
+		"inconshreveable/log15": "log15",
+		"apex/log":              "apex/log",
+		"go.pedge.io/lion":      "lion",
+		"rs/zerolog":            "zerolog",
+	}
+)
+
+func main() {
+	flag.Parse()
+	if err := do(); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func do() error {
+	tmplData, err := getTmplData()
+	if err != nil {
+		return err
+	}
+	data, err := ioutil.ReadAll(os.Stdin)
+	if err != nil {
+		return err
+	}
+	t, err := template.New("tmpl").Parse(string(data))
+	if err != nil {
+		return err
+	}
+	if err := t.Execute(os.Stdout, tmplData); err != nil {
+		return err
+	}
+	return nil
+}
+
+func getTmplData() (*tmplData, error) {
+	tmplData := &tmplData{}
+	rows, err := getBenchmarkRows("BenchmarkAddingFields")
+	if err != nil {
+		return nil, err
+	}
+	tmplData.BenchmarkAddingFields = rows
+	rows, err = getBenchmarkRows("BenchmarkAccumulatedContext")
+	if err != nil {
+		return nil, err
+	}
+	tmplData.BenchmarkAccumulatedContext = rows
+	rows, err = getBenchmarkRows("BenchmarkWithoutFields")
+	if err != nil {
+		return nil, err
+	}
+	tmplData.BenchmarkWithoutFields = rows
+	return tmplData, nil
+}
+
+func getBenchmarkRows(benchmarkName string) (string, error) {
+	benchmarkOutput, err := getBenchmarkOutput(benchmarkName)
+	if err != nil {
+		return "", err
+	}
+	var benchmarkRows []*benchmarkRow
+	for libraryName := range libraryNameToMarkdownName {
+		benchmarkRow, err := getBenchmarkRow(benchmarkOutput, benchmarkName, libraryName)
+		if err != nil {
+			return "", err
+		}
+		if benchmarkRow == nil {
+			continue
+		}
+		benchmarkRows = append(benchmarkRows, benchmarkRow)
+	}
+	sort.Sort(benchmarkRowsByTime(benchmarkRows))
+	rows := []string{
+		"| Package | Time | Objects Allocated |",
+		"| :--- | :---: | :---: |",
+	}
+	for _, benchmarkRow := range benchmarkRows {
+		rows = append(rows, benchmarkRow.String())
+	}
+	return strings.Join(rows, "\n"), nil
+}
+
+func getBenchmarkRow(input []string, benchmarkName string, libraryName string) (*benchmarkRow, error) {
+	line, err := findUniqueSubstring(input, fmt.Sprintf("%s/%s-", benchmarkName, libraryName))
+	if err != nil {
+		return nil, err
+	}
+	if line == "" {
+		return nil, nil
+	}
+	split := strings.Split(line, "\t")
+	if len(split) < 5 {
+		return nil, fmt.Errorf("unknown benchmark line: %s", line)
+	}
+	duration, err := time.ParseDuration(strings.Replace(strings.TrimSuffix(strings.TrimSpace(split[2]), "/op"), " ", "", -1))
+	if err != nil {
+		return nil, err
+	}
+	allocatedBytes, err := strconv.Atoi(strings.TrimSuffix(strings.TrimSpace(split[3]), " B/op"))
+	if err != nil {
+		return nil, err
+	}
+	allocatedObjects, err := strconv.Atoi(strings.TrimSuffix(strings.TrimSpace(split[4]), " allocs/op"))
+	if err != nil {
+		return nil, err
+	}
+	return &benchmarkRow{
+		libraryNameToMarkdownName[libraryName],
+		duration,
+		allocatedBytes,
+		allocatedObjects,
+	}, nil
+}
+
+func findUniqueSubstring(input []string, substring string) (string, error) {
+	var output string
+	for _, line := range input {
+		if strings.Contains(line, substring) {
+			if output != "" {
+				return "", fmt.Errorf("input has duplicate substring %s", substring)
+			}
+			output = line
+		}
+	}
+	return output, nil
+}
+
+func getBenchmarkOutput(benchmarkName string) ([]string, error) {
+	return getOutput("go", "test", fmt.Sprintf("-bench=%s", benchmarkName), "-benchmem", "./benchmarks")
+}
+
+func getOutput(name string, arg ...string) ([]string, error) {
+	output, err := exec.Command(name, arg...).CombinedOutput()
+	if err != nil {
+		return nil, fmt.Errorf("error running %s %s: %v\n%s", name, strings.Join(arg, " "), err, string(output))
+	}
+	return strings.Split(string(output), "\n"), nil
+}
+
+type tmplData struct {
+	BenchmarkAddingFields       string
+	BenchmarkAccumulatedContext string
+	BenchmarkWithoutFields      string
+}
+
+type benchmarkRow struct {
+	Name             string
+	Time             time.Duration
+	AllocatedBytes   int
+	AllocatedObjects int
+}
+
+func (b *benchmarkRow) String() string {
+	return fmt.Sprintf("| %s | %d ns/op | %d allocs/op |", b.Name, b.Time.Nanoseconds(), b.AllocatedObjects)
+}
+
+type benchmarkRowsByTime []*benchmarkRow
+
+func (b benchmarkRowsByTime) Len() int      { return len(b) }
+func (b benchmarkRowsByTime) Swap(i, j int) { b[i], b[j] = b[j], b[i] }
+func (b benchmarkRowsByTime) Less(i, j int) bool {
+	left, right := b[i], b[j]
+	leftZap, rightZap := strings.Contains(left.Name, "zap"), strings.Contains(right.Name, "zap")
+
+	// If neither benchmark is for zap or both are, sort by time.
+	if !(leftZap || rightZap) || (leftZap && rightZap) {
+		return left.Time.Nanoseconds() < right.Time.Nanoseconds()
+	}
+	// Sort zap benchmark first.
+	return leftZap
+}
diff --git a/vendor/go.uber.org/zap/level.go b/vendor/go.uber.org/zap/level.go
new file mode 100644
index 0000000..166101f
--- /dev/null
+++ b/vendor/go.uber.org/zap/level.go
@@ -0,0 +1,132 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"go.uber.org/atomic"
+	"go.uber.org/zap/zapcore"
+)
+
+const (
+	// DebugLevel logs are typically voluminous, and are usually disabled in
+	// production.
+	DebugLevel = zapcore.DebugLevel
+	// InfoLevel is the default logging priority.
+	InfoLevel = zapcore.InfoLevel
+	// WarnLevel logs are more important than Info, but don't need individual
+	// human review.
+	WarnLevel = zapcore.WarnLevel
+	// ErrorLevel logs are high-priority. If an application is running smoothly,
+	// it shouldn't generate any error-level logs.
+	ErrorLevel = zapcore.ErrorLevel
+	// DPanicLevel logs are particularly important errors. In development the
+	// logger panics after writing the message.
+	DPanicLevel = zapcore.DPanicLevel
+	// PanicLevel logs a message, then panics.
+	PanicLevel = zapcore.PanicLevel
+	// FatalLevel logs a message, then calls os.Exit(1).
+	FatalLevel = zapcore.FatalLevel
+)
+
+// LevelEnablerFunc is a convenient way to implement zapcore.LevelEnabler with
+// an anonymous function.
+//
+// It's particularly useful when splitting log output between different
+// outputs (e.g., standard error and standard out). For sample code, see the
+// package-level AdvancedConfiguration example.
+type LevelEnablerFunc func(zapcore.Level) bool
+
+// Enabled calls the wrapped function.
+func (f LevelEnablerFunc) Enabled(lvl zapcore.Level) bool { return f(lvl) }
+
+// An AtomicLevel is an atomically changeable, dynamic logging level. It lets
+// you safely change the log level of a tree of loggers (the root logger and
+// any children created by adding context) at runtime.
+//
+// The AtomicLevel itself is an http.Handler that serves a JSON endpoint to
+// alter its level.
+//
+// AtomicLevels must be created with the NewAtomicLevel constructor to allocate
+// their internal atomic pointer.
+type AtomicLevel struct {
+	l *atomic.Int32
+}
+
+// NewAtomicLevel creates an AtomicLevel with InfoLevel and above logging
+// enabled.
+func NewAtomicLevel() AtomicLevel {
+	return AtomicLevel{
+		l: atomic.NewInt32(int32(InfoLevel)),
+	}
+}
+
+// NewAtomicLevelAt is a convienence function that creates an AtomicLevel
+// and then calls SetLevel with the given level.
+func NewAtomicLevelAt(l zapcore.Level) AtomicLevel {
+	a := NewAtomicLevel()
+	a.SetLevel(l)
+	return a
+}
+
+// Enabled implements the zapcore.LevelEnabler interface, which allows the
+// AtomicLevel to be used in place of traditional static levels.
+func (lvl AtomicLevel) Enabled(l zapcore.Level) bool {
+	return lvl.Level().Enabled(l)
+}
+
+// Level returns the minimum enabled log level.
+func (lvl AtomicLevel) Level() zapcore.Level {
+	return zapcore.Level(int8(lvl.l.Load()))
+}
+
+// SetLevel alters the logging level.
+func (lvl AtomicLevel) SetLevel(l zapcore.Level) {
+	lvl.l.Store(int32(l))
+}
+
+// String returns the string representation of the underlying Level.
+func (lvl AtomicLevel) String() string {
+	return lvl.Level().String()
+}
+
+// UnmarshalText unmarshals the text to an AtomicLevel. It uses the same text
+// representations as the static zapcore.Levels ("debug", "info", "warn",
+// "error", "dpanic", "panic", and "fatal").
+func (lvl *AtomicLevel) UnmarshalText(text []byte) error {
+	if lvl.l == nil {
+		lvl.l = &atomic.Int32{}
+	}
+
+	var l zapcore.Level
+	if err := l.UnmarshalText(text); err != nil {
+		return err
+	}
+
+	lvl.SetLevel(l)
+	return nil
+}
+
+// MarshalText marshals the AtomicLevel to a byte slice. It uses the same
+// text representation as the static zapcore.Levels ("debug", "info", "warn",
+// "error", "dpanic", "panic", and "fatal").
+func (lvl AtomicLevel) MarshalText() (text []byte, err error) {
+	return lvl.Level().MarshalText()
+}
diff --git a/vendor/go.uber.org/zap/level_test.go b/vendor/go.uber.org/zap/level_test.go
new file mode 100644
index 0000000..a8fb650
--- /dev/null
+++ b/vendor/go.uber.org/zap/level_test.go
@@ -0,0 +1,117 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"sync"
+	"testing"
+
+	"go.uber.org/zap/zapcore"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestLevelEnablerFunc(t *testing.T) {
+	enab := LevelEnablerFunc(func(l zapcore.Level) bool { return l == zapcore.InfoLevel })
+	tests := []struct {
+		level   zapcore.Level
+		enabled bool
+	}{
+		{DebugLevel, false},
+		{InfoLevel, true},
+		{WarnLevel, false},
+		{ErrorLevel, false},
+		{DPanicLevel, false},
+		{PanicLevel, false},
+		{FatalLevel, false},
+	}
+	for _, tt := range tests {
+		assert.Equal(t, tt.enabled, enab.Enabled(tt.level), "Unexpected result applying LevelEnablerFunc to %s", tt.level)
+	}
+}
+
+func TestNewAtomicLevel(t *testing.T) {
+	lvl := NewAtomicLevel()
+	assert.Equal(t, InfoLevel, lvl.Level(), "Unexpected initial level.")
+	lvl.SetLevel(ErrorLevel)
+	assert.Equal(t, ErrorLevel, lvl.Level(), "Unexpected level after SetLevel.")
+	lvl = NewAtomicLevelAt(WarnLevel)
+	assert.Equal(t, WarnLevel, lvl.Level(), "Unexpected level after SetLevel.")
+}
+
+func TestAtomicLevelMutation(t *testing.T) {
+	lvl := NewAtomicLevel()
+	lvl.SetLevel(WarnLevel)
+	// Trigger races for non-atomic level mutations.
+	proceed := make(chan struct{})
+	wg := &sync.WaitGroup{}
+	runConcurrently(10, 100, wg, func() {
+		<-proceed
+		assert.Equal(t, WarnLevel, lvl.Level())
+	})
+	runConcurrently(10, 100, wg, func() {
+		<-proceed
+		lvl.SetLevel(WarnLevel)
+	})
+	close(proceed)
+	wg.Wait()
+}
+
+func TestAtomicLevelText(t *testing.T) {
+	tests := []struct {
+		text   string
+		expect zapcore.Level
+		err    bool
+	}{
+		{"debug", DebugLevel, false},
+		{"info", InfoLevel, false},
+		{"", InfoLevel, false},
+		{"warn", WarnLevel, false},
+		{"error", ErrorLevel, false},
+		{"dpanic", DPanicLevel, false},
+		{"panic", PanicLevel, false},
+		{"fatal", FatalLevel, false},
+		{"foobar", InfoLevel, true},
+	}
+
+	for _, tt := range tests {
+		var lvl AtomicLevel
+		// Test both initial unmarshaling and overwriting existing value.
+		for i := 0; i < 2; i++ {
+			if tt.err {
+				assert.Error(t, lvl.UnmarshalText([]byte(tt.text)), "Expected unmarshaling %q to fail.", tt.text)
+			} else {
+				assert.NoError(t, lvl.UnmarshalText([]byte(tt.text)), "Expected unmarshaling %q to succeed.", tt.text)
+			}
+			assert.Equal(t, tt.expect, lvl.Level(), "Unexpected level after unmarshaling.")
+			lvl.SetLevel(InfoLevel)
+		}
+
+		// Test marshalling
+		if tt.text != "" && !tt.err {
+			lvl.SetLevel(tt.expect)
+			marshaled, err := lvl.MarshalText()
+			assert.NoError(t, err, `Unexpected error marshalling level "%v" to text.`, tt.expect)
+			assert.Equal(t, tt.text, string(marshaled), "Expected marshaled text to match")
+			assert.Equal(t, tt.text, lvl.String(), "Expected Stringer call to match")
+		}
+	}
+}
diff --git a/vendor/go.uber.org/zap/logger.go b/vendor/go.uber.org/zap/logger.go
new file mode 100644
index 0000000..7d8824b
--- /dev/null
+++ b/vendor/go.uber.org/zap/logger.go
@@ -0,0 +1,305 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"runtime"
+	"strings"
+	"time"
+
+	"go.uber.org/zap/zapcore"
+)
+
+// A Logger provides fast, leveled, structured logging. All methods are safe
+// for concurrent use.
+//
+// The Logger is designed for contexts in which every microsecond and every
+// allocation matters, so its API intentionally favors performance and type
+// safety over brevity. For most applications, the SugaredLogger strikes a
+// better balance between performance and ergonomics.
+type Logger struct {
+	core zapcore.Core
+
+	development bool
+	name        string
+	errorOutput zapcore.WriteSyncer
+
+	addCaller bool
+	addStack  zapcore.LevelEnabler
+
+	callerSkip int
+}
+
+// New constructs a new Logger from the provided zapcore.Core and Options. If
+// the passed zapcore.Core is nil, it falls back to using a no-op
+// implementation.
+//
+// This is the most flexible way to construct a Logger, but also the most
+// verbose. For typical use cases, the highly-opinionated presets
+// (NewProduction, NewDevelopment, and NewExample) or the Config struct are
+// more convenient.
+//
+// For sample code, see the package-level AdvancedConfiguration example.
+func New(core zapcore.Core, options ...Option) *Logger {
+	if core == nil {
+		return NewNop()
+	}
+	log := &Logger{
+		core:        core,
+		errorOutput: zapcore.Lock(os.Stderr),
+		addStack:    zapcore.FatalLevel + 1,
+	}
+	return log.WithOptions(options...)
+}
+
+// NewNop returns a no-op Logger. It never writes out logs or internal errors,
+// and it never runs user-defined hooks.
+//
+// Using WithOptions to replace the Core or error output of a no-op Logger can
+// re-enable logging.
+func NewNop() *Logger {
+	return &Logger{
+		core:        zapcore.NewNopCore(),
+		errorOutput: zapcore.AddSync(ioutil.Discard),
+		addStack:    zapcore.FatalLevel + 1,
+	}
+}
+
+// NewProduction builds a sensible production Logger that writes InfoLevel and
+// above logs to standard error as JSON.
+//
+// It's a shortcut for NewProductionConfig().Build(...Option).
+func NewProduction(options ...Option) (*Logger, error) {
+	return NewProductionConfig().Build(options...)
+}
+
+// NewDevelopment builds a development Logger that writes DebugLevel and above
+// logs to standard error in a human-friendly format.
+//
+// It's a shortcut for NewDevelopmentConfig().Build(...Option).
+func NewDevelopment(options ...Option) (*Logger, error) {
+	return NewDevelopmentConfig().Build(options...)
+}
+
+// NewExample builds a Logger that's designed for use in zap's testable
+// examples. It writes DebugLevel and above logs to standard out as JSON, but
+// omits the timestamp and calling function to keep example output
+// short and deterministic.
+func NewExample(options ...Option) *Logger {
+	encoderCfg := zapcore.EncoderConfig{
+		MessageKey:     "msg",
+		LevelKey:       "level",
+		NameKey:        "logger",
+		EncodeLevel:    zapcore.LowercaseLevelEncoder,
+		EncodeTime:     zapcore.ISO8601TimeEncoder,
+		EncodeDuration: zapcore.StringDurationEncoder,
+	}
+	core := zapcore.NewCore(zapcore.NewJSONEncoder(encoderCfg), os.Stdout, DebugLevel)
+	return New(core).WithOptions(options...)
+}
+
+// Sugar wraps the Logger to provide a more ergonomic, but slightly slower,
+// API. Sugaring a Logger is quite inexpensive, so it's reasonable for a
+// single application to use both Loggers and SugaredLoggers, converting
+// between them on the boundaries of performance-sensitive code.
+func (log *Logger) Sugar() *SugaredLogger {
+	core := log.clone()
+	core.callerSkip += 2
+	return &SugaredLogger{core}
+}
+
+// Named adds a new path segment to the logger's name. Segments are joined by
+// periods. By default, Loggers are unnamed.
+func (log *Logger) Named(s string) *Logger {
+	if s == "" {
+		return log
+	}
+	l := log.clone()
+	if log.name == "" {
+		l.name = s
+	} else {
+		l.name = strings.Join([]string{l.name, s}, ".")
+	}
+	return l
+}
+
+// WithOptions clones the current Logger, applies the supplied Options, and
+// returns the resulting Logger. It's safe to use concurrently.
+func (log *Logger) WithOptions(opts ...Option) *Logger {
+	c := log.clone()
+	for _, opt := range opts {
+		opt.apply(c)
+	}
+	return c
+}
+
+// With creates a child logger and adds structured context to it. Fields added
+// to the child don't affect the parent, and vice versa.
+func (log *Logger) With(fields ...zapcore.Field) *Logger {
+	if len(fields) == 0 {
+		return log
+	}
+	l := log.clone()
+	l.core = l.core.With(fields)
+	return l
+}
+
+// Check returns a CheckedEntry if logging a message at the specified level
+// is enabled. It's a completely optional optimization; in high-performance
+// applications, Check can help avoid allocating a slice to hold fields.
+func (log *Logger) Check(lvl zapcore.Level, msg string) *zapcore.CheckedEntry {
+	return log.check(lvl, msg)
+}
+
+// Debug logs a message at DebugLevel. The message includes any fields passed
+// at the log site, as well as any fields accumulated on the logger.
+func (log *Logger) Debug(msg string, fields ...zapcore.Field) {
+	if ce := log.check(DebugLevel, msg); ce != nil {
+		ce.Write(fields...)
+	}
+}
+
+// Info logs a message at InfoLevel. The message includes any fields passed
+// at the log site, as well as any fields accumulated on the logger.
+func (log *Logger) Info(msg string, fields ...zapcore.Field) {
+	if ce := log.check(InfoLevel, msg); ce != nil {
+		ce.Write(fields...)
+	}
+}
+
+// Warn logs a message at WarnLevel. The message includes any fields passed
+// at the log site, as well as any fields accumulated on the logger.
+func (log *Logger) Warn(msg string, fields ...zapcore.Field) {
+	if ce := log.check(WarnLevel, msg); ce != nil {
+		ce.Write(fields...)
+	}
+}
+
+// Error logs a message at ErrorLevel. The message includes any fields passed
+// at the log site, as well as any fields accumulated on the logger.
+func (log *Logger) Error(msg string, fields ...zapcore.Field) {
+	if ce := log.check(ErrorLevel, msg); ce != nil {
+		ce.Write(fields...)
+	}
+}
+
+// DPanic logs a message at DPanicLevel. The message includes any fields
+// passed at the log site, as well as any fields accumulated on the logger.
+//
+// If the logger is in development mode, it then panics (DPanic means
+// "development panic"). This is useful for catching errors that are
+// recoverable, but shouldn't ever happen.
+func (log *Logger) DPanic(msg string, fields ...zapcore.Field) {
+	if ce := log.check(DPanicLevel, msg); ce != nil {
+		ce.Write(fields...)
+	}
+}
+
+// Panic logs a message at PanicLevel. The message includes any fields passed
+// at the log site, as well as any fields accumulated on the logger.
+//
+// The logger then panics, even if logging at PanicLevel is disabled.
+func (log *Logger) Panic(msg string, fields ...zapcore.Field) {
+	if ce := log.check(PanicLevel, msg); ce != nil {
+		ce.Write(fields...)
+	}
+}
+
+// Fatal logs a message at FatalLevel. The message includes any fields passed
+// at the log site, as well as any fields accumulated on the logger.
+//
+// The logger then calls os.Exit(1), even if logging at FatalLevel is
+// disabled.
+func (log *Logger) Fatal(msg string, fields ...zapcore.Field) {
+	if ce := log.check(FatalLevel, msg); ce != nil {
+		ce.Write(fields...)
+	}
+}
+
+// Sync calls the underlying Core's Sync method, flushing any buffered log
+// entries. Applications should take care to call Sync before exiting.
+func (log *Logger) Sync() error {
+	return log.core.Sync()
+}
+
+// Core returns the Logger's underlying zapcore.Core.
+func (log *Logger) Core() zapcore.Core {
+	return log.core
+}
+
+func (log *Logger) clone() *Logger {
+	copy := *log
+	return &copy
+}
+
+func (log *Logger) check(lvl zapcore.Level, msg string) *zapcore.CheckedEntry {
+	// check must always be called directly by a method in the Logger interface
+	// (e.g., Check, Info, Fatal).
+	const callerSkipOffset = 2
+
+	// Create basic checked entry thru the core; this will be non-nil if the
+	// log message will actually be written somewhere.
+	ent := zapcore.Entry{
+		LoggerName: log.name,
+		Time:       time.Now(),
+		Level:      lvl,
+		Message:    msg,
+	}
+	ce := log.core.Check(ent, nil)
+	willWrite := ce != nil
+
+	// Set up any required terminal behavior.
+	switch ent.Level {
+	case zapcore.PanicLevel:
+		ce = ce.Should(ent, zapcore.WriteThenPanic)
+	case zapcore.FatalLevel:
+		ce = ce.Should(ent, zapcore.WriteThenFatal)
+	case zapcore.DPanicLevel:
+		if log.development {
+			ce = ce.Should(ent, zapcore.WriteThenPanic)
+		}
+	}
+
+	// Only do further annotation if we're going to write this message; checked
+	// entries that exist only for terminal behavior don't benefit from
+	// annotation.
+	if !willWrite {
+		return ce
+	}
+
+	// Thread the error output through to the CheckedEntry.
+	ce.ErrorOutput = log.errorOutput
+	if log.addCaller {
+		ce.Entry.Caller = zapcore.NewEntryCaller(runtime.Caller(log.callerSkip + callerSkipOffset))
+		if !ce.Entry.Caller.Defined {
+			fmt.Fprintf(log.errorOutput, "%v Logger.check error: failed to get caller\n", time.Now().UTC())
+			log.errorOutput.Sync()
+		}
+	}
+	if log.addStack.Enabled(ce.Entry.Level) {
+		ce.Entry.Stack = Stack("").String
+	}
+
+	return ce
+}
diff --git a/vendor/go.uber.org/zap/logger_bench_test.go b/vendor/go.uber.org/zap/logger_bench_test.go
new file mode 100644
index 0000000..1ba7c75
--- /dev/null
+++ b/vendor/go.uber.org/zap/logger_bench_test.go
@@ -0,0 +1,222 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"errors"
+	"testing"
+	"time"
+
+	"go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest"
+)
+
+type user struct {
+	Name      string
+	Email     string
+	CreatedAt time.Time
+}
+
+func (u *user) MarshalLogObject(enc zapcore.ObjectEncoder) error {
+	enc.AddString("name", u.Name)
+	enc.AddString("email", u.Email)
+	enc.AddInt64("created_at", u.CreatedAt.UnixNano())
+	return nil
+}
+
+var _jane = &user{
+	Name:      "Jane Doe",
+	Email:     "jane@test.com",
+	CreatedAt: time.Date(1980, 1, 1, 12, 0, 0, 0, time.UTC),
+}
+
+func withBenchedLogger(b *testing.B, f func(*Logger)) {
+	logger := New(
+		zapcore.NewCore(
+			zapcore.NewJSONEncoder(NewProductionConfig().EncoderConfig),
+			&zaptest.Discarder{},
+			DebugLevel,
+		))
+	b.ResetTimer()
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			f(logger)
+		}
+	})
+}
+
+func BenchmarkNoContext(b *testing.B) {
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("No context.")
+	})
+}
+
+func BenchmarkBoolField(b *testing.B) {
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("Boolean.", Bool("foo", true))
+	})
+}
+
+func BenchmarkByteStringField(b *testing.B) {
+	val := []byte("bar")
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("ByteString.", ByteString("foo", val))
+	})
+}
+
+func BenchmarkFloat64Field(b *testing.B) {
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("Floating point.", Float64("foo", 3.14))
+	})
+}
+
+func BenchmarkIntField(b *testing.B) {
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("Integer.", Int("foo", 42))
+	})
+}
+
+func BenchmarkInt64Field(b *testing.B) {
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("64-bit integer.", Int64("foo", 42))
+	})
+}
+
+func BenchmarkStringField(b *testing.B) {
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("Strings.", String("foo", "bar"))
+	})
+}
+
+func BenchmarkStringerField(b *testing.B) {
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("Level.", Stringer("foo", InfoLevel))
+	})
+}
+
+func BenchmarkTimeField(b *testing.B) {
+	t := time.Unix(0, 0)
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("Time.", Time("foo", t))
+	})
+}
+
+func BenchmarkDurationField(b *testing.B) {
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("Duration", Duration("foo", time.Second))
+	})
+}
+
+func BenchmarkErrorField(b *testing.B) {
+	err := errors.New("egad")
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("Error.", Error(err))
+	})
+}
+
+func BenchmarkErrorsField(b *testing.B) {
+	errs := []error{
+		errors.New("egad"),
+		errors.New("oh no"),
+		errors.New("dear me"),
+		errors.New("such fail"),
+	}
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("Errors.", Errors("errors", errs))
+	})
+}
+
+func BenchmarkStackField(b *testing.B) {
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("Error.", Stack("stacktrace"))
+	})
+}
+
+func BenchmarkObjectField(b *testing.B) {
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("Arbitrary ObjectMarshaler.", Object("user", _jane))
+	})
+}
+
+func BenchmarkReflectField(b *testing.B) {
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("Reflection-based serialization.", Reflect("user", _jane))
+	})
+}
+
+func BenchmarkAddCallerHook(b *testing.B) {
+	logger := New(
+		zapcore.NewCore(
+			zapcore.NewJSONEncoder(NewProductionConfig().EncoderConfig),
+			&zaptest.Discarder{},
+			InfoLevel,
+		),
+		AddCaller(),
+	)
+	b.ResetTimer()
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			logger.Info("Caller.")
+		}
+	})
+}
+
+func Benchmark10Fields(b *testing.B) {
+	withBenchedLogger(b, func(log *Logger) {
+		log.Info("Ten fields, passed at the log site.",
+			Int("one", 1),
+			Int("two", 2),
+			Int("three", 3),
+			Int("four", 4),
+			Int("five", 5),
+			Int("six", 6),
+			Int("seven", 7),
+			Int("eight", 8),
+			Int("nine", 9),
+			Int("ten", 10),
+		)
+	})
+}
+
+func Benchmark100Fields(b *testing.B) {
+	const batchSize = 50
+	logger := New(zapcore.NewCore(
+		zapcore.NewJSONEncoder(NewProductionConfig().EncoderConfig),
+		&zaptest.Discarder{},
+		DebugLevel,
+	))
+
+	// Don't include allocating these helper slices in the benchmark. Since
+	// access to them isn't synchronized, we can't run the benchmark in
+	// parallel.
+	first := make([]zapcore.Field, batchSize)
+	second := make([]zapcore.Field, batchSize)
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		for i := 0; i < batchSize; i++ {
+			// We're duplicating keys, but that doesn't affect performance.
+			first[i] = Int("foo", i)
+			second[i] = Int("foo", i+batchSize)
+		}
+		logger.With(first...).Info("Child loggers with lots of context.", second...)
+	}
+}
diff --git a/vendor/go.uber.org/zap/logger_test.go b/vendor/go.uber.org/zap/logger_test.go
new file mode 100644
index 0000000..0b0cf62
--- /dev/null
+++ b/vendor/go.uber.org/zap/logger_test.go
@@ -0,0 +1,432 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"errors"
+	"sync"
+	"testing"
+
+	"go.uber.org/zap/internal/exit"
+	"go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest"
+	"go.uber.org/zap/zaptest/observer"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/atomic"
+)
+
+func makeCountingHook() (func(zapcore.Entry) error, *atomic.Int64) {
+	count := &atomic.Int64{}
+	h := func(zapcore.Entry) error {
+		count.Inc()
+		return nil
+	}
+	return h, count
+}
+
+func TestLoggerAtomicLevel(t *testing.T) {
+	// Test that the dynamic level applies to all ancestors and descendants.
+	dl := NewAtomicLevel()
+
+	withLogger(t, dl, nil, func(grandparent *Logger, _ *observer.ObservedLogs) {
+		parent := grandparent.With(Int("generation", 1))
+		child := parent.With(Int("generation", 2))
+
+		tests := []struct {
+			setLevel  zapcore.Level
+			testLevel zapcore.Level
+			enabled   bool
+		}{
+			{DebugLevel, DebugLevel, true},
+			{InfoLevel, DebugLevel, false},
+			{WarnLevel, PanicLevel, true},
+		}
+
+		for _, tt := range tests {
+			dl.SetLevel(tt.setLevel)
+			for _, logger := range []*Logger{grandparent, parent, child} {
+				if tt.enabled {
+					assert.NotNil(
+						t,
+						logger.Check(tt.testLevel, ""),
+						"Expected level %s to be enabled after setting level %s.", tt.testLevel, tt.setLevel,
+					)
+				} else {
+					assert.Nil(
+						t,
+						logger.Check(tt.testLevel, ""),
+						"Expected level %s to be enabled after setting level %s.", tt.testLevel, tt.setLevel,
+					)
+				}
+			}
+		}
+	})
+}
+
+func TestLoggerInitialFields(t *testing.T) {
+	fieldOpts := opts(Fields(Int("foo", 42), String("bar", "baz")))
+	withLogger(t, DebugLevel, fieldOpts, func(logger *Logger, logs *observer.ObservedLogs) {
+		logger.Info("")
+		assert.Equal(
+			t,
+			observer.LoggedEntry{Context: []zapcore.Field{Int("foo", 42), String("bar", "baz")}},
+			logs.AllUntimed()[0],
+			"Unexpected output with initial fields set.",
+		)
+	})
+}
+
+func TestLoggerWith(t *testing.T) {
+	fieldOpts := opts(Fields(Int("foo", 42)))
+	withLogger(t, DebugLevel, fieldOpts, func(logger *Logger, logs *observer.ObservedLogs) {
+		// Child loggers should have copy-on-write semantics, so two children
+		// shouldn't stomp on each other's fields or affect the parent's fields.
+		logger.With(String("one", "two")).Info("")
+		logger.With(String("three", "four")).Info("")
+		logger.Info("")
+
+		assert.Equal(t, []observer.LoggedEntry{
+			{Context: []zapcore.Field{Int("foo", 42), String("one", "two")}},
+			{Context: []zapcore.Field{Int("foo", 42), String("three", "four")}},
+			{Context: []zapcore.Field{Int("foo", 42)}},
+		}, logs.AllUntimed(), "Unexpected cross-talk between child loggers.")
+	})
+}
+
+func TestLoggerLogPanic(t *testing.T) {
+	for _, tt := range []struct {
+		do       func(*Logger)
+		should   bool
+		expected string
+	}{
+		{func(logger *Logger) { logger.Check(PanicLevel, "bar").Write() }, true, "bar"},
+		{func(logger *Logger) { logger.Panic("baz") }, true, "baz"},
+	} {
+		withLogger(t, DebugLevel, nil, func(logger *Logger, logs *observer.ObservedLogs) {
+			if tt.should {
+				assert.Panics(t, func() { tt.do(logger) }, "Expected panic")
+			} else {
+				assert.NotPanics(t, func() { tt.do(logger) }, "Expected no panic")
+			}
+
+			output := logs.AllUntimed()
+			assert.Equal(t, 1, len(output), "Unexpected number of logs.")
+			assert.Equal(t, 0, len(output[0].Context), "Unexpected context on first log.")
+			assert.Equal(
+				t,
+				zapcore.Entry{Message: tt.expected, Level: PanicLevel},
+				output[0].Entry,
+				"Unexpected output from panic-level Log.",
+			)
+		})
+	}
+}
+
+func TestLoggerLogFatal(t *testing.T) {
+	for _, tt := range []struct {
+		do       func(*Logger)
+		expected string
+	}{
+		{func(logger *Logger) { logger.Check(FatalLevel, "bar").Write() }, "bar"},
+		{func(logger *Logger) { logger.Fatal("baz") }, "baz"},
+	} {
+		withLogger(t, DebugLevel, nil, func(logger *Logger, logs *observer.ObservedLogs) {
+			stub := exit.WithStub(func() {
+				tt.do(logger)
+			})
+			assert.True(t, stub.Exited, "Expected Fatal logger call to terminate process.")
+			output := logs.AllUntimed()
+			assert.Equal(t, 1, len(output), "Unexpected number of logs.")
+			assert.Equal(t, 0, len(output[0].Context), "Unexpected context on first log.")
+			assert.Equal(
+				t,
+				zapcore.Entry{Message: tt.expected, Level: FatalLevel},
+				output[0].Entry,
+				"Unexpected output from fatal-level Log.",
+			)
+		})
+	}
+}
+
+func TestLoggerLeveledMethods(t *testing.T) {
+	withLogger(t, DebugLevel, nil, func(logger *Logger, logs *observer.ObservedLogs) {
+		tests := []struct {
+			method        func(string, ...zapcore.Field)
+			expectedLevel zapcore.Level
+		}{
+			{logger.Debug, DebugLevel},
+			{logger.Info, InfoLevel},
+			{logger.Warn, WarnLevel},
+			{logger.Error, ErrorLevel},
+			{logger.DPanic, DPanicLevel},
+		}
+		for i, tt := range tests {
+			tt.method("")
+			output := logs.AllUntimed()
+			assert.Equal(t, i+1, len(output), "Unexpected number of logs.")
+			assert.Equal(t, 0, len(output[i].Context), "Unexpected context on first log.")
+			assert.Equal(
+				t,
+				zapcore.Entry{Level: tt.expectedLevel},
+				output[i].Entry,
+				"Unexpected output from %s-level logger method.", tt.expectedLevel)
+		}
+	})
+}
+
+func TestLoggerAlwaysPanics(t *testing.T) {
+	// Users can disable writing out panic-level logs, but calls to logger.Panic()
+	// should still call panic().
+	withLogger(t, FatalLevel, nil, func(logger *Logger, logs *observer.ObservedLogs) {
+		msg := "Even if output is disabled, logger.Panic should always panic."
+		assert.Panics(t, func() { logger.Panic("foo") }, msg)
+		assert.Panics(t, func() {
+			if ce := logger.Check(PanicLevel, "foo"); ce != nil {
+				ce.Write()
+			}
+		}, msg)
+		assert.Equal(t, 0, logs.Len(), "Panics shouldn't be written out if PanicLevel is disabled.")
+	})
+}
+
+func TestLoggerAlwaysFatals(t *testing.T) {
+	// Users can disable writing out fatal-level logs, but calls to logger.Fatal()
+	// should still terminate the process.
+	withLogger(t, FatalLevel+1, nil, func(logger *Logger, logs *observer.ObservedLogs) {
+		stub := exit.WithStub(func() { logger.Fatal("") })
+		assert.True(t, stub.Exited, "Expected calls to logger.Fatal to terminate process.")
+
+		stub = exit.WithStub(func() {
+			if ce := logger.Check(FatalLevel, ""); ce != nil {
+				ce.Write()
+			}
+		})
+		assert.True(t, stub.Exited, "Expected calls to logger.Check(FatalLevel, ...) to terminate process.")
+
+		assert.Equal(t, 0, logs.Len(), "Shouldn't write out logs when fatal-level logging is disabled.")
+	})
+}
+
+func TestLoggerDPanic(t *testing.T) {
+	withLogger(t, DebugLevel, nil, func(logger *Logger, logs *observer.ObservedLogs) {
+		assert.NotPanics(t, func() { logger.DPanic("") })
+		assert.Equal(
+			t,
+			[]observer.LoggedEntry{{Entry: zapcore.Entry{Level: DPanicLevel}, Context: []zapcore.Field{}}},
+			logs.AllUntimed(),
+			"Unexpected log output from DPanic in production mode.",
+		)
+	})
+	withLogger(t, DebugLevel, opts(Development()), func(logger *Logger, logs *observer.ObservedLogs) {
+		assert.Panics(t, func() { logger.DPanic("") })
+		assert.Equal(
+			t,
+			[]observer.LoggedEntry{{Entry: zapcore.Entry{Level: DPanicLevel}, Context: []zapcore.Field{}}},
+			logs.AllUntimed(),
+			"Unexpected log output from DPanic in development mode.",
+		)
+	})
+}
+
+func TestLoggerNoOpsDisabledLevels(t *testing.T) {
+	withLogger(t, WarnLevel, nil, func(logger *Logger, logs *observer.ObservedLogs) {
+		logger.Info("silence!")
+		assert.Equal(
+			t,
+			[]observer.LoggedEntry{},
+			logs.AllUntimed(),
+			"Expected logging at a disabled level to produce no output.",
+		)
+	})
+}
+
+func TestLoggerNames(t *testing.T) {
+	tests := []struct {
+		names    []string
+		expected string
+	}{
+		{nil, ""},
+		{[]string{""}, ""},
+		{[]string{"foo"}, "foo"},
+		{[]string{"foo", ""}, "foo"},
+		{[]string{"foo", "bar"}, "foo.bar"},
+		{[]string{"foo.bar", "baz"}, "foo.bar.baz"},
+		// Garbage in, garbage out.
+		{[]string{"foo.", "bar"}, "foo..bar"},
+		{[]string{"foo", ".bar"}, "foo..bar"},
+		{[]string{"foo.", ".bar"}, "foo...bar"},
+	}
+
+	for _, tt := range tests {
+		withLogger(t, DebugLevel, nil, func(log *Logger, logs *observer.ObservedLogs) {
+			for _, n := range tt.names {
+				log = log.Named(n)
+			}
+			log.Info("")
+			require.Equal(t, 1, logs.Len(), "Expected only one log entry to be written.")
+			assert.Equal(t, tt.expected, logs.AllUntimed()[0].Entry.LoggerName, "Unexpected logger name.")
+		})
+		withSugar(t, DebugLevel, nil, func(log *SugaredLogger, logs *observer.ObservedLogs) {
+			for _, n := range tt.names {
+				log = log.Named(n)
+			}
+			log.Infow("")
+			require.Equal(t, 1, logs.Len(), "Expected only one log entry to be written.")
+			assert.Equal(t, tt.expected, logs.AllUntimed()[0].Entry.LoggerName, "Unexpected logger name.")
+		})
+	}
+}
+
+func TestLoggerWriteFailure(t *testing.T) {
+	errSink := &zaptest.Buffer{}
+	logger := New(
+		zapcore.NewCore(
+			zapcore.NewJSONEncoder(NewProductionConfig().EncoderConfig),
+			zapcore.Lock(zapcore.AddSync(zaptest.FailWriter{})),
+			DebugLevel,
+		),
+		ErrorOutput(errSink),
+	)
+
+	logger.Info("foo")
+	// Should log the error.
+	assert.Regexp(t, `write error: failed`, errSink.Stripped(), "Expected to log the error to the error output.")
+	assert.True(t, errSink.Called(), "Expected logging an internal error to call Sync the error sink.")
+}
+
+func TestLoggerSync(t *testing.T) {
+	withLogger(t, DebugLevel, nil, func(logger *Logger, _ *observer.ObservedLogs) {
+		assert.NoError(t, logger.Sync(), "Expected syncing a test logger to succeed.")
+		assert.NoError(t, logger.Sugar().Sync(), "Expected syncing a sugared logger to succeed.")
+	})
+}
+
+func TestLoggerSyncFail(t *testing.T) {
+	noSync := &zaptest.Buffer{}
+	err := errors.New("fail")
+	noSync.SetError(err)
+	logger := New(zapcore.NewCore(
+		zapcore.NewJSONEncoder(zapcore.EncoderConfig{}),
+		noSync,
+		DebugLevel,
+	))
+	assert.Equal(t, err, logger.Sync(), "Expected Logger.Sync to propagate errors.")
+	assert.Equal(t, err, logger.Sugar().Sync(), "Expected SugaredLogger.Sync to propagate errors.")
+}
+
+func TestLoggerAddCaller(t *testing.T) {
+	tests := []struct {
+		options []Option
+		pat     string
+	}{
+		{opts(AddCaller()), `.+/logger_test.go:[\d]+$`},
+		{opts(AddCaller(), AddCallerSkip(1), AddCallerSkip(-1)), `.+/zap/logger_test.go:[\d]+$`},
+		{opts(AddCaller(), AddCallerSkip(1)), `.+/zap/common_test.go:[\d]+$`},
+		{opts(AddCaller(), AddCallerSkip(1), AddCallerSkip(3)), `.+/src/runtime/.*:[\d]+$`},
+	}
+	for _, tt := range tests {
+		withLogger(t, DebugLevel, tt.options, func(logger *Logger, logs *observer.ObservedLogs) {
+			// Make sure that sugaring and desugaring resets caller skip properly.
+			logger = logger.Sugar().Desugar()
+			logger.Info("")
+			output := logs.AllUntimed()
+			assert.Equal(t, 1, len(output), "Unexpected number of logs written out.")
+			assert.Regexp(
+				t,
+				tt.pat,
+				output[0].Entry.Caller,
+				"Expected to find package name and file name in output.",
+			)
+		})
+	}
+}
+
+func TestLoggerAddCallerFail(t *testing.T) {
+	errBuf := &zaptest.Buffer{}
+	withLogger(t, DebugLevel, opts(AddCaller(), ErrorOutput(errBuf)), func(log *Logger, logs *observer.ObservedLogs) {
+		log.callerSkip = 1e3
+		log.Info("Failure.")
+		assert.Regexp(
+			t,
+			`Logger.check error: failed to get caller`,
+			errBuf.String(),
+			"Didn't find expected failure message.",
+		)
+		assert.Equal(
+			t,
+			logs.AllUntimed()[0].Entry.Message,
+			"Failure.",
+			"Expected original message to survive failures in runtime.Caller.")
+	})
+}
+
+func TestLoggerReplaceCore(t *testing.T) {
+	replace := WrapCore(func(zapcore.Core) zapcore.Core {
+		return zapcore.NewNopCore()
+	})
+	withLogger(t, DebugLevel, opts(replace), func(logger *Logger, logs *observer.ObservedLogs) {
+		logger.Debug("")
+		logger.Info("")
+		logger.Warn("")
+		assert.Equal(t, 0, logs.Len(), "Expected no-op core to write no logs.")
+	})
+}
+
+func TestLoggerHooks(t *testing.T) {
+	hook, seen := makeCountingHook()
+	withLogger(t, DebugLevel, opts(Hooks(hook)), func(logger *Logger, logs *observer.ObservedLogs) {
+		logger.Debug("")
+		logger.Info("")
+	})
+	assert.Equal(t, int64(2), seen.Load(), "Hook saw an unexpected number of logs.")
+}
+
+func TestLoggerConcurrent(t *testing.T) {
+	withLogger(t, DebugLevel, nil, func(logger *Logger, logs *observer.ObservedLogs) {
+		child := logger.With(String("foo", "bar"))
+
+		wg := &sync.WaitGroup{}
+		runConcurrently(5, 10, wg, func() {
+			logger.Info("", String("foo", "bar"))
+		})
+		runConcurrently(5, 10, wg, func() {
+			child.Info("")
+		})
+
+		wg.Wait()
+
+		// Make sure the output doesn't contain interspersed entries.
+		assert.Equal(t, 100, logs.Len(), "Unexpected number of logs written out.")
+		for _, obs := range logs.AllUntimed() {
+			assert.Equal(
+				t,
+				observer.LoggedEntry{
+					Entry:   zapcore.Entry{Level: InfoLevel},
+					Context: []zapcore.Field{String("foo", "bar")},
+				},
+				obs,
+				"Unexpected log output.",
+			)
+		}
+	})
+}
diff --git a/vendor/go.uber.org/zap/options.go b/vendor/go.uber.org/zap/options.go
new file mode 100644
index 0000000..d0f9422
--- /dev/null
+++ b/vendor/go.uber.org/zap/options.go
@@ -0,0 +1,109 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import "go.uber.org/zap/zapcore"
+
+// An Option configures a Logger.
+type Option interface {
+	apply(*Logger)
+}
+
+// optionFunc wraps a func so it satisfies the Option interface.
+type optionFunc func(*Logger)
+
+func (f optionFunc) apply(log *Logger) {
+	f(log)
+}
+
+// WrapCore wraps or replaces the Logger's underlying zapcore.Core.
+func WrapCore(f func(zapcore.Core) zapcore.Core) Option {
+	return optionFunc(func(log *Logger) {
+		log.core = f(log.core)
+	})
+}
+
+// Hooks registers functions which will be called each time the Logger writes
+// out an Entry. Repeated use of Hooks is additive.
+//
+// Hooks are useful for simple side effects, like capturing metrics for the
+// number of emitted logs. More complex side effects, including anything that
+// requires access to the Entry's structured fields, should be implemented as
+// a zapcore.Core instead. See zapcore.RegisterHooks for details.
+func Hooks(hooks ...func(zapcore.Entry) error) Option {
+	return optionFunc(func(log *Logger) {
+		log.core = zapcore.RegisterHooks(log.core, hooks...)
+	})
+}
+
+// Fields adds fields to the Logger.
+func Fields(fs ...zapcore.Field) Option {
+	return optionFunc(func(log *Logger) {
+		log.core = log.core.With(fs)
+	})
+}
+
+// ErrorOutput sets the destination for errors generated by the Logger. Note
+// that this option only affects internal errors; for sample code that sends
+// error-level logs to a different location from info- and debug-level logs,
+// see the package-level AdvancedConfiguration example.
+//
+// The supplied WriteSyncer must be safe for concurrent use. The Open and
+// zapcore.Lock functions are the simplest ways to protect files with a mutex.
+func ErrorOutput(w zapcore.WriteSyncer) Option {
+	return optionFunc(func(log *Logger) {
+		log.errorOutput = w
+	})
+}
+
+// Development puts the logger in development mode, which makes DPanic-level
+// logs panic instead of simply logging an error.
+func Development() Option {
+	return optionFunc(func(log *Logger) {
+		log.development = true
+	})
+}
+
+// AddCaller configures the Logger to annotate each message with the filename
+// and line number of zap's caller.
+func AddCaller() Option {
+	return optionFunc(func(log *Logger) {
+		log.addCaller = true
+	})
+}
+
+// AddCallerSkip increases the number of callers skipped by caller annotation
+// (as enabled by the AddCaller option). When building wrappers around the
+// Logger and SugaredLogger, supplying this Option prevents zap from always
+// reporting the wrapper code as the caller.
+func AddCallerSkip(skip int) Option {
+	return optionFunc(func(log *Logger) {
+		log.callerSkip += skip
+	})
+}
+
+// AddStacktrace configures the Logger to record a stack trace for all messages at
+// or above a given level.
+func AddStacktrace(lvl zapcore.LevelEnabler) Option {
+	return optionFunc(func(log *Logger) {
+		log.addStack = lvl
+	})
+}
diff --git a/vendor/go.uber.org/zap/scripts/cover.sh b/vendor/go.uber.org/zap/scripts/cover.sh
new file mode 100755
index 0000000..0da503c
--- /dev/null
+++ b/vendor/go.uber.org/zap/scripts/cover.sh
@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+set -e
+echo "" > cover.out
+
+for d in $(go list $@); do
+    go test -race -coverprofile=profile.out $d
+    if [ -f profile.out ]; then
+        cat profile.out >> cover.out
+        rm profile.out
+    fi
+done
diff --git a/vendor/go.uber.org/zap/stacktrace.go b/vendor/go.uber.org/zap/stacktrace.go
new file mode 100644
index 0000000..100fac2
--- /dev/null
+++ b/vendor/go.uber.org/zap/stacktrace.go
@@ -0,0 +1,126 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"runtime"
+	"strings"
+	"sync"
+
+	"go.uber.org/zap/internal/bufferpool"
+)
+
+const _zapPackage = "go.uber.org/zap"
+
+var (
+	_stacktracePool = sync.Pool{
+		New: func() interface{} {
+			return newProgramCounters(64)
+		},
+	}
+
+	// We add "." and "/" suffixes to the package name to ensure we only match
+	// the exact package and not any package with the same prefix.
+	_zapStacktracePrefixes       = addPrefix(_zapPackage, ".", "/")
+	_zapStacktraceVendorContains = addPrefix("/vendor/", _zapStacktracePrefixes...)
+)
+
+func takeStacktrace() string {
+	buffer := bufferpool.Get()
+	defer buffer.Free()
+	programCounters := _stacktracePool.Get().(*programCounters)
+	defer _stacktracePool.Put(programCounters)
+
+	var numFrames int
+	for {
+		// Skip the call to runtime.Counters and takeStacktrace so that the
+		// program counters start at the caller of takeStacktrace.
+		numFrames = runtime.Callers(2, programCounters.pcs)
+		if numFrames < len(programCounters.pcs) {
+			break
+		}
+		// Don't put the too-short counter slice back into the pool; this lets
+		// the pool adjust if we consistently take deep stacktraces.
+		programCounters = newProgramCounters(len(programCounters.pcs) * 2)
+	}
+
+	i := 0
+	skipZapFrames := true // skip all consecutive zap frames at the beginning.
+	frames := runtime.CallersFrames(programCounters.pcs[:numFrames])
+
+	// Note: On the last iteration, frames.Next() returns false, with a valid
+	// frame, but we ignore this frame. The last frame is a a runtime frame which
+	// adds noise, since it's only either runtime.main or runtime.goexit.
+	for frame, more := frames.Next(); more; frame, more = frames.Next() {
+		if skipZapFrames && isZapFrame(frame.Function) {
+			continue
+		} else {
+			skipZapFrames = false
+		}
+
+		if i != 0 {
+			buffer.AppendByte('\n')
+		}
+		i++
+		buffer.AppendString(frame.Function)
+		buffer.AppendByte('\n')
+		buffer.AppendByte('\t')
+		buffer.AppendString(frame.File)
+		buffer.AppendByte(':')
+		buffer.AppendInt(int64(frame.Line))
+	}
+
+	return buffer.String()
+}
+
+func isZapFrame(function string) bool {
+	for _, prefix := range _zapStacktracePrefixes {
+		if strings.HasPrefix(function, prefix) {
+			return true
+		}
+	}
+
+	// We can't use a prefix match here since the location of the vendor
+	// directory affects the prefix. Instead we do a contains match.
+	for _, contains := range _zapStacktraceVendorContains {
+		if strings.Contains(function, contains) {
+			return true
+		}
+	}
+
+	return false
+}
+
+type programCounters struct {
+	pcs []uintptr
+}
+
+func newProgramCounters(size int) *programCounters {
+	return &programCounters{make([]uintptr, size)}
+}
+
+func addPrefix(prefix string, ss ...string) []string {
+	withPrefix := make([]string, len(ss))
+	for i, s := range ss {
+		withPrefix[i] = prefix + s
+	}
+	return withPrefix
+}
diff --git a/vendor/go.uber.org/zap/stacktrace_ext_test.go b/vendor/go.uber.org/zap/stacktrace_ext_test.go
new file mode 100644
index 0000000..0edf5e1
--- /dev/null
+++ b/vendor/go.uber.org/zap/stacktrace_ext_test.go
@@ -0,0 +1,161 @@
+// Copyright (c) 2016, 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap_test
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// _zapPackages are packages that we search for in the logging output to match a
+// zap stack frame. It is different from _zapStacktracePrefixes which  is only
+// intended to match on the function name, while this is on the full output
+// which includes filenames.
+var _zapPackages = []string{
+	"go.uber.org/zap.",
+	"go.uber.org/zap/zapcore.",
+}
+
+func TestStacktraceFiltersZapLog(t *testing.T) {
+	withLogger(t, func(logger *zap.Logger, out *bytes.Buffer) {
+		logger.Error("test log")
+		logger.Sugar().Error("sugar test log")
+
+		require.Contains(t, out.String(), "TestStacktraceFiltersZapLog", "Should not strip out non-zap import")
+		verifyNoZap(t, out.String())
+	})
+}
+
+func TestStacktraceFiltersZapMarshal(t *testing.T) {
+	withLogger(t, func(logger *zap.Logger, out *bytes.Buffer) {
+		marshal := func(enc zapcore.ObjectEncoder) error {
+			logger.Warn("marshal caused warn")
+			enc.AddString("f", "v")
+			return nil
+		}
+		logger.Error("test log", zap.Object("obj", zapcore.ObjectMarshalerFunc(marshal)))
+
+		logs := out.String()
+
+		// The marshal function (which will be under the test function) should not be stripped.
+		const marshalFnPrefix = "TestStacktraceFiltersZapMarshal."
+		require.Contains(t, logs, marshalFnPrefix, "Should not strip out marshal call")
+
+		// There should be no zap stack traces before that point.
+		marshalIndex := strings.Index(logs, marshalFnPrefix)
+		verifyNoZap(t, logs[:marshalIndex])
+
+		// After that point, there should be zap stack traces - we don't want to strip out
+		// the Marshal caller information.
+		for _, fnPrefix := range _zapPackages {
+			require.Contains(t, logs[marshalIndex:], fnPrefix, "Missing zap caller stack for Marshal")
+		}
+	})
+}
+
+func TestStacktraceFiltersVendorZap(t *testing.T) {
+	// We need to simulate a zap as a vendor library, so we're going to create a fake GOPATH
+	// and run the above test which will contain zap in the vendor directory.
+	withGoPath(t, func(goPath string) {
+		curDir, err := os.Getwd()
+		require.NoError(t, err, "Failed to get current directory")
+
+		testDir := filepath.Join(goPath, "src/go.uber.org/zap_test/")
+		vendorDir := filepath.Join(testDir, "vendor")
+		require.NoError(t, os.MkdirAll(testDir, 0777), "Failed to create source director")
+
+		curFile := getSelfFilename(t)
+		//copyFile(t, curFile, filepath.Join(testDir, curFile))
+		setupSymlink(t, curFile, filepath.Join(testDir, curFile))
+
+		// Set up symlinks for zap, and for any test dependencies.
+		setupSymlink(t, curDir, filepath.Join(vendorDir, "go.uber.org/zap"))
+		for _, testDep := range []string{"github.com/stretchr/testify"} {
+			setupSymlink(t, filepath.Join(curDir, "vendor", testDep), filepath.Join(vendorDir, testDep))
+		}
+
+		// Now run the above test which ensures we filter out zap stacktraces, but this time
+		// zap is in a vendor
+		cmd := exec.Command("go", "test", "-v", "-run", "TestStacktraceFiltersZap")
+		cmd.Dir = testDir
+		out, err := cmd.CombinedOutput()
+		require.NoError(t, err, "Failed to run test in vendor directory, output: %s", out)
+		assert.Contains(t, string(out), "PASS")
+	})
+}
+
+// withLogger sets up a logger with a real encoder set up, so that any marshal functions are called.
+// The inbuilt observer does not call Marshal for objects/arrays, which we need for some tests.
+func withLogger(t *testing.T, fn func(logger *zap.Logger, out *bytes.Buffer)) {
+	buf := &bytes.Buffer{}
+	encoder := zapcore.NewConsoleEncoder(zap.NewDevelopmentEncoderConfig())
+	core := zapcore.NewCore(encoder, zapcore.AddSync(buf), zapcore.DebugLevel)
+	logger := zap.New(core, zap.AddStacktrace(zap.DebugLevel))
+	fn(logger, buf)
+}
+
+func verifyNoZap(t *testing.T, logs string) {
+	for _, fnPrefix := range _zapPackages {
+		require.NotContains(t, logs, fnPrefix, "Should not strip out marshal call")
+	}
+}
+
+func withGoPath(t *testing.T, f func(goPath string)) {
+	goPath, err := ioutil.TempDir("", "gopath")
+	require.NoError(t, err, "Failed to create temporary directory for GOPATH")
+	//defer os.RemoveAll(goPath)
+
+	os.Setenv("GOPATH", goPath)
+	defer os.Setenv("GOPATH", os.Getenv("GOPATH"))
+
+	f(goPath)
+}
+
+func getSelfFilename(t *testing.T) string {
+	_, file, _, ok := runtime.Caller(0)
+	require.True(t, ok, "Failed to get caller information to identify local file")
+
+	return filepath.Base(file)
+}
+
+func setupSymlink(t *testing.T, src, dst string) {
+	// Make sure the destination directory exists.
+	os.MkdirAll(filepath.Dir(dst), 0777)
+
+	// Get absolute path of the source for the symlink, otherwise we can create a symlink
+	// that uses relative paths.
+	srcAbs, err := filepath.Abs(src)
+	require.NoError(t, err, "Failed to get absolute path")
+
+	require.NoError(t, os.Symlink(srcAbs, dst), "Failed to set up symlink")
+}
diff --git a/vendor/go.uber.org/zap/stacktrace_test.go b/vendor/go.uber.org/zap/stacktrace_test.go
new file mode 100644
index 0000000..3c9a41c
--- /dev/null
+++ b/vendor/go.uber.org/zap/stacktrace_test.go
@@ -0,0 +1,75 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestTakeStacktrace(t *testing.T) {
+	trace := takeStacktrace()
+	lines := strings.Split(trace, "\n")
+	require.True(t, len(lines) > 0, "Expected stacktrace to have at least one frame.")
+	assert.Contains(
+		t,
+		lines[0],
+		"testing.",
+		"Expected stacktrace to start with the test runner (zap frames are filtered out) %s.", lines[0],
+	)
+}
+
+func TestIsZapFrame(t *testing.T) {
+	zapFrames := []string{
+		"go.uber.org/zap.Stack",
+		"go.uber.org/zap.(*SugaredLogger).log",
+		"go.uber.org/zap/zapcore.(ArrayMarshalerFunc).MarshalLogArray",
+		"github.com/uber/tchannel-go/vendor/go.uber.org/zap.Stack",
+		"github.com/uber/tchannel-go/vendor/go.uber.org/zap.(*SugaredLogger).log",
+		"github.com/uber/tchannel-go/vendor/go.uber.org/zap/zapcore.(ArrayMarshalerFunc).MarshalLogArray",
+	}
+	nonZapFrames := []string{
+		"github.com/uber/tchannel-go.NewChannel",
+		"go.uber.org/not-zap.New",
+		"go.uber.org/zapext.ctx",
+		"go.uber.org/zap_ext/ctx.New",
+	}
+
+	t.Run("zap frames", func(t *testing.T) {
+		for _, f := range zapFrames {
+			require.True(t, isZapFrame(f), f)
+		}
+	})
+	t.Run("non-zap frames", func(t *testing.T) {
+		for _, f := range nonZapFrames {
+			require.False(t, isZapFrame(f), f)
+		}
+	})
+}
+
+func BenchmarkTakeStacktrace(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		takeStacktrace()
+	}
+}
diff --git a/vendor/go.uber.org/zap/sugar.go b/vendor/go.uber.org/zap/sugar.go
new file mode 100644
index 0000000..9cda009
--- /dev/null
+++ b/vendor/go.uber.org/zap/sugar.go
@@ -0,0 +1,304 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"fmt"
+
+	"go.uber.org/zap/zapcore"
+
+	"go.uber.org/multierr"
+)
+
+const (
+	_oddNumberErrMsg    = "Ignored key without a value."
+	_nonStringKeyErrMsg = "Ignored key-value pairs with non-string keys."
+)
+
+// A SugaredLogger wraps the base Logger functionality in a slower, but less
+// verbose, API. Any Logger can be converted to a SugaredLogger with its Sugar
+// method.
+//
+// Unlike the Logger, the SugaredLogger doesn't insist on structured logging.
+// For each log level, it exposes three methods: one for loosely-typed
+// structured logging, one for println-style formatting, and one for
+// printf-style formatting. For example, SugaredLoggers can produce InfoLevel
+// output with Infow ("info with" structured context), Info, or Infof.
+type SugaredLogger struct {
+	base *Logger
+}
+
+// Desugar unwraps a SugaredLogger, exposing the original Logger. Desugaring
+// is quite inexpensive, so it's reasonable for a single application to use
+// both Loggers and SugaredLoggers, converting between them on the boundaries
+// of performance-sensitive code.
+func (s *SugaredLogger) Desugar() *Logger {
+	base := s.base.clone()
+	base.callerSkip -= 2
+	return base
+}
+
+// Named adds a sub-scope to the logger's name. See Logger.Named for details.
+func (s *SugaredLogger) Named(name string) *SugaredLogger {
+	return &SugaredLogger{base: s.base.Named(name)}
+}
+
+// With adds a variadic number of fields to the logging context. It accepts a
+// mix of strongly-typed zapcore.Field objects and loosely-typed key-value
+// pairs. When processing pairs, the first element of the pair is used as the
+// field key and the second as the field value.
+//
+// For example,
+//   sugaredLogger.With(
+//     "hello", "world",
+//     "failure", errors.New("oh no"),
+//     Stack(),
+//     "count", 42,
+//     "user", User{Name: "alice"},
+//  )
+// is the equivalent of
+//   unsugared.With(
+//     String("hello", "world"),
+//     String("failure", "oh no"),
+//     Stack(),
+//     Int("count", 42),
+//     Object("user", User{Name: "alice"}),
+//   )
+//
+// Note that the keys in key-value pairs should be strings. In development,
+// passing a non-string key panics. In production, the logger is more
+// forgiving: a separate error is logged, but the key-value pair is skipped
+// and execution continues. Passing an orphaned key triggers similar behavior:
+// panics in development and errors in production.
+func (s *SugaredLogger) With(args ...interface{}) *SugaredLogger {
+	return &SugaredLogger{base: s.base.With(s.sweetenFields(args)...)}
+}
+
+// Debug uses fmt.Sprint to construct and log a message.
+func (s *SugaredLogger) Debug(args ...interface{}) {
+	s.log(DebugLevel, "", args, nil)
+}
+
+// Info uses fmt.Sprint to construct and log a message.
+func (s *SugaredLogger) Info(args ...interface{}) {
+	s.log(InfoLevel, "", args, nil)
+}
+
+// Warn uses fmt.Sprint to construct and log a message.
+func (s *SugaredLogger) Warn(args ...interface{}) {
+	s.log(WarnLevel, "", args, nil)
+}
+
+// Error uses fmt.Sprint to construct and log a message.
+func (s *SugaredLogger) Error(args ...interface{}) {
+	s.log(ErrorLevel, "", args, nil)
+}
+
+// DPanic uses fmt.Sprint to construct and log a message. In development, the
+// logger then panics. (See DPanicLevel for details.)
+func (s *SugaredLogger) DPanic(args ...interface{}) {
+	s.log(DPanicLevel, "", args, nil)
+}
+
+// Panic uses fmt.Sprint to construct and log a message, then panics.
+func (s *SugaredLogger) Panic(args ...interface{}) {
+	s.log(PanicLevel, "", args, nil)
+}
+
+// Fatal uses fmt.Sprint to construct and log a message, then calls os.Exit.
+func (s *SugaredLogger) Fatal(args ...interface{}) {
+	s.log(FatalLevel, "", args, nil)
+}
+
+// Debugf uses fmt.Sprintf to log a templated message.
+func (s *SugaredLogger) Debugf(template string, args ...interface{}) {
+	s.log(DebugLevel, template, args, nil)
+}
+
+// Infof uses fmt.Sprintf to log a templated message.
+func (s *SugaredLogger) Infof(template string, args ...interface{}) {
+	s.log(InfoLevel, template, args, nil)
+}
+
+// Warnf uses fmt.Sprintf to log a templated message.
+func (s *SugaredLogger) Warnf(template string, args ...interface{}) {
+	s.log(WarnLevel, template, args, nil)
+}
+
+// Errorf uses fmt.Sprintf to log a templated message.
+func (s *SugaredLogger) Errorf(template string, args ...interface{}) {
+	s.log(ErrorLevel, template, args, nil)
+}
+
+// DPanicf uses fmt.Sprintf to log a templated message. In development, the
+// logger then panics. (See DPanicLevel for details.)
+func (s *SugaredLogger) DPanicf(template string, args ...interface{}) {
+	s.log(DPanicLevel, template, args, nil)
+}
+
+// Panicf uses fmt.Sprintf to log a templated message, then panics.
+func (s *SugaredLogger) Panicf(template string, args ...interface{}) {
+	s.log(PanicLevel, template, args, nil)
+}
+
+// Fatalf uses fmt.Sprintf to log a templated message, then calls os.Exit.
+func (s *SugaredLogger) Fatalf(template string, args ...interface{}) {
+	s.log(FatalLevel, template, args, nil)
+}
+
+// Debugw logs a message with some additional context. The variadic key-value
+// pairs are treated as they are in With.
+//
+// When debug-level logging is disabled, this is much faster than
+//  s.With(keysAndValues).Debug(msg)
+func (s *SugaredLogger) Debugw(msg string, keysAndValues ...interface{}) {
+	s.log(DebugLevel, msg, nil, keysAndValues)
+}
+
+// Infow logs a message with some additional context. The variadic key-value
+// pairs are treated as they are in With.
+func (s *SugaredLogger) Infow(msg string, keysAndValues ...interface{}) {
+	s.log(InfoLevel, msg, nil, keysAndValues)
+}
+
+// Warnw logs a message with some additional context. The variadic key-value
+// pairs are treated as they are in With.
+func (s *SugaredLogger) Warnw(msg string, keysAndValues ...interface{}) {
+	s.log(WarnLevel, msg, nil, keysAndValues)
+}
+
+// Errorw logs a message with some additional context. The variadic key-value
+// pairs are treated as they are in With.
+func (s *SugaredLogger) Errorw(msg string, keysAndValues ...interface{}) {
+	s.log(ErrorLevel, msg, nil, keysAndValues)
+}
+
+// DPanicw logs a message with some additional context. In development, the
+// logger then panics. (See DPanicLevel for details.) The variadic key-value
+// pairs are treated as they are in With.
+func (s *SugaredLogger) DPanicw(msg string, keysAndValues ...interface{}) {
+	s.log(DPanicLevel, msg, nil, keysAndValues)
+}
+
+// Panicw logs a message with some additional context, then panics. The
+// variadic key-value pairs are treated as they are in With.
+func (s *SugaredLogger) Panicw(msg string, keysAndValues ...interface{}) {
+	s.log(PanicLevel, msg, nil, keysAndValues)
+}
+
+// Fatalw logs a message with some additional context, then calls os.Exit. The
+// variadic key-value pairs are treated as they are in With.
+func (s *SugaredLogger) Fatalw(msg string, keysAndValues ...interface{}) {
+	s.log(FatalLevel, msg, nil, keysAndValues)
+}
+
+// Sync flushes any buffered log entries.
+func (s *SugaredLogger) Sync() error {
+	return s.base.Sync()
+}
+
+func (s *SugaredLogger) log(lvl zapcore.Level, template string, fmtArgs []interface{}, context []interface{}) {
+	// If logging at this level is completely disabled, skip the overhead of
+	// string formatting.
+	if lvl < DPanicLevel && !s.base.Core().Enabled(lvl) {
+		return
+	}
+
+	// Format with Sprint, Sprintf, or neither.
+	msg := template
+	if msg == "" && len(fmtArgs) > 0 {
+		msg = fmt.Sprint(fmtArgs...)
+	} else if msg != "" && len(fmtArgs) > 0 {
+		msg = fmt.Sprintf(template, fmtArgs...)
+	}
+
+	if ce := s.base.Check(lvl, msg); ce != nil {
+		ce.Write(s.sweetenFields(context)...)
+	}
+}
+
+func (s *SugaredLogger) sweetenFields(args []interface{}) []zapcore.Field {
+	if len(args) == 0 {
+		return nil
+	}
+
+	// Allocate enough space for the worst case; if users pass only structured
+	// fields, we shouldn't penalize them with extra allocations.
+	fields := make([]zapcore.Field, 0, len(args))
+	var invalid invalidPairs
+
+	for i := 0; i < len(args); {
+		// This is a strongly-typed field. Consume it and move on.
+		if f, ok := args[i].(zapcore.Field); ok {
+			fields = append(fields, f)
+			i++
+			continue
+		}
+
+		// Make sure this element isn't a dangling key.
+		if i == len(args)-1 {
+			s.base.DPanic(_oddNumberErrMsg, Any("ignored", args[i]))
+			break
+		}
+
+		// Consume this value and the next, treating them as a key-value pair. If the
+		// key isn't a string, add this pair to the slice of invalid pairs.
+		key, val := args[i], args[i+1]
+		if keyStr, ok := key.(string); !ok {
+			// Subsequent errors are likely, so allocate once up front.
+			if cap(invalid) == 0 {
+				invalid = make(invalidPairs, 0, len(args)/2)
+			}
+			invalid = append(invalid, invalidPair{i, key, val})
+		} else {
+			fields = append(fields, Any(keyStr, val))
+		}
+		i += 2
+	}
+
+	// If we encountered any invalid key-value pairs, log an error.
+	if len(invalid) > 0 {
+		s.base.DPanic(_nonStringKeyErrMsg, Array("invalid", invalid))
+	}
+	return fields
+}
+
+type invalidPair struct {
+	position   int
+	key, value interface{}
+}
+
+func (p invalidPair) MarshalLogObject(enc zapcore.ObjectEncoder) error {
+	enc.AddInt64("position", int64(p.position))
+	Any("key", p.key).AddTo(enc)
+	Any("value", p.value).AddTo(enc)
+	return nil
+}
+
+type invalidPairs []invalidPair
+
+func (ps invalidPairs) MarshalLogArray(enc zapcore.ArrayEncoder) error {
+	var err error
+	for i := range ps {
+		err = multierr.Append(err, enc.AppendObject(ps[i]))
+	}
+	return err
+}
diff --git a/vendor/go.uber.org/zap/sugar_test.go b/vendor/go.uber.org/zap/sugar_test.go
new file mode 100644
index 0000000..69eb1fa
--- /dev/null
+++ b/vendor/go.uber.org/zap/sugar_test.go
@@ -0,0 +1,374 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"testing"
+
+	"go.uber.org/zap/internal/exit"
+	"go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest"
+	"go.uber.org/zap/zaptest/observer"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSugarWith(t *testing.T) {
+	// Convenience functions to create expected error logs.
+	ignored := func(msg interface{}) observer.LoggedEntry {
+		return observer.LoggedEntry{
+			Entry:   zapcore.Entry{Level: DPanicLevel, Message: _oddNumberErrMsg},
+			Context: []zapcore.Field{Any("ignored", msg)},
+		}
+	}
+	nonString := func(pairs ...invalidPair) observer.LoggedEntry {
+		return observer.LoggedEntry{
+			Entry:   zapcore.Entry{Level: DPanicLevel, Message: _nonStringKeyErrMsg},
+			Context: []zapcore.Field{Array("invalid", invalidPairs(pairs))},
+		}
+	}
+
+	tests := []struct {
+		desc     string
+		args     []interface{}
+		expected []zapcore.Field
+		errLogs  []observer.LoggedEntry
+	}{
+		{
+			desc:     "nil args",
+			args:     nil,
+			expected: []zapcore.Field{},
+			errLogs:  nil,
+		},
+		{
+			desc:     "empty slice of args",
+			args:     []interface{}{},
+			expected: []zapcore.Field{},
+			errLogs:  nil,
+		},
+		{
+			desc:     "just a dangling key",
+			args:     []interface{}{"should ignore"},
+			expected: []zapcore.Field{},
+			errLogs:  []observer.LoggedEntry{ignored("should ignore")},
+		},
+		{
+			desc:     "well-formed key-value pairs",
+			args:     []interface{}{"foo", 42, "true", "bar"},
+			expected: []zapcore.Field{Int("foo", 42), String("true", "bar")},
+			errLogs:  nil,
+		},
+		{
+			desc:     "just a structured field",
+			args:     []interface{}{Int("foo", 42)},
+			expected: []zapcore.Field{Int("foo", 42)},
+			errLogs:  nil,
+		},
+		{
+			desc:     "structured field and a dangling key",
+			args:     []interface{}{Int("foo", 42), "dangling"},
+			expected: []zapcore.Field{Int("foo", 42)},
+			errLogs:  []observer.LoggedEntry{ignored("dangling")},
+		},
+		{
+			desc:     "structured field and a dangling non-string key",
+			args:     []interface{}{Int("foo", 42), 13},
+			expected: []zapcore.Field{Int("foo", 42)},
+			errLogs:  []observer.LoggedEntry{ignored(13)},
+		},
+		{
+			desc:     "key-value pair and a dangling key",
+			args:     []interface{}{"foo", 42, "dangling"},
+			expected: []zapcore.Field{Int("foo", 42)},
+			errLogs:  []observer.LoggedEntry{ignored("dangling")},
+		},
+		{
+			desc:     "pairs, a structured field, and a dangling key",
+			args:     []interface{}{"first", "field", Int("foo", 42), "baz", "quux", "dangling"},
+			expected: []zapcore.Field{String("first", "field"), Int("foo", 42), String("baz", "quux")},
+			errLogs:  []observer.LoggedEntry{ignored("dangling")},
+		},
+		{
+			desc:     "one non-string key",
+			args:     []interface{}{"foo", 42, true, "bar"},
+			expected: []zapcore.Field{Int("foo", 42)},
+			errLogs:  []observer.LoggedEntry{nonString(invalidPair{2, true, "bar"})},
+		},
+		{
+			desc:     "pairs, structured fields, non-string keys, and a dangling key",
+			args:     []interface{}{"foo", 42, true, "bar", Int("structure", 11), 42, "reversed", "baz", "quux", "dangling"},
+			expected: []zapcore.Field{Int("foo", 42), Int("structure", 11), String("baz", "quux")},
+			errLogs: []observer.LoggedEntry{
+				ignored("dangling"),
+				nonString(invalidPair{2, true, "bar"}, invalidPair{5, 42, "reversed"}),
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		withSugar(t, DebugLevel, nil, func(logger *SugaredLogger, logs *observer.ObservedLogs) {
+			logger.With(tt.args...).Info("")
+			output := logs.AllUntimed()
+			if len(tt.errLogs) > 0 {
+				for i := range tt.errLogs {
+					assert.Equal(t, tt.errLogs[i], output[i], "Unexpected error log at position %d for scenario %s.", i, tt.desc)
+				}
+			}
+			assert.Equal(t, len(tt.errLogs)+1, len(output), "Expected only one non-error message to be logged in scenario %s.", tt.desc)
+			assert.Equal(t, tt.expected, output[len(tt.errLogs)].Context, "Unexpected message context in scenario %s.", tt.desc)
+		})
+	}
+}
+
+func TestSugarFieldsInvalidPairs(t *testing.T) {
+	withSugar(t, DebugLevel, nil, func(logger *SugaredLogger, logs *observer.ObservedLogs) {
+		logger.With(42, "foo", []string{"bar"}, "baz").Info("")
+		output := logs.AllUntimed()
+
+		// Double-check that the actual message was logged.
+		require.Equal(t, 2, len(output), "Unexpected number of entries logged.")
+		require.Equal(t, observer.LoggedEntry{Context: []zapcore.Field{}}, output[1], "Unexpected non-error log entry.")
+
+		// Assert that the error message's structured fields serialize properly.
+		require.Equal(t, 1, len(output[0].Context), "Expected one field in error entry context.")
+		enc := zapcore.NewMapObjectEncoder()
+		output[0].Context[0].AddTo(enc)
+		assert.Equal(t, []interface{}{
+			map[string]interface{}{"position": int64(0), "key": int64(42), "value": "foo"},
+			map[string]interface{}{"position": int64(2), "key": []interface{}{"bar"}, "value": "baz"},
+		}, enc.Fields["invalid"], "Unexpected output when logging invalid key-value pairs.")
+	})
+}
+
+type stringerF func() string
+
+func (f stringerF) String() string { return f() }
+
+func TestSugarStructuredLogging(t *testing.T) {
+	tests := []struct {
+		msg       string
+		expectMsg string
+	}{
+		{"foo", "foo"},
+		{"", ""},
+	}
+
+	// Common to all test cases.
+	context := []interface{}{"foo", "bar"}
+	extra := []interface{}{"baz", false}
+	expectedFields := []zapcore.Field{String("foo", "bar"), Bool("baz", false)}
+
+	for _, tt := range tests {
+		withSugar(t, DebugLevel, nil, func(logger *SugaredLogger, logs *observer.ObservedLogs) {
+			logger.With(context...).Debugw(tt.msg, extra...)
+			logger.With(context...).Infow(tt.msg, extra...)
+			logger.With(context...).Warnw(tt.msg, extra...)
+			logger.With(context...).Errorw(tt.msg, extra...)
+			logger.With(context...).DPanicw(tt.msg, extra...)
+
+			expected := make([]observer.LoggedEntry, 5)
+			for i, lvl := range []zapcore.Level{DebugLevel, InfoLevel, WarnLevel, ErrorLevel, DPanicLevel} {
+				expected[i] = observer.LoggedEntry{
+					Entry:   zapcore.Entry{Message: tt.expectMsg, Level: lvl},
+					Context: expectedFields,
+				}
+			}
+			assert.Equal(t, expected, logs.AllUntimed(), "Unexpected log output.")
+		})
+	}
+}
+
+func TestSugarConcatenatingLogging(t *testing.T) {
+	tests := []struct {
+		args   []interface{}
+		expect string
+	}{
+		{[]interface{}{nil}, "<nil>"},
+	}
+
+	// Common to all test cases.
+	context := []interface{}{"foo", "bar"}
+	expectedFields := []zapcore.Field{String("foo", "bar")}
+
+	for _, tt := range tests {
+		withSugar(t, DebugLevel, nil, func(logger *SugaredLogger, logs *observer.ObservedLogs) {
+			logger.With(context...).Debug(tt.args...)
+			logger.With(context...).Info(tt.args...)
+			logger.With(context...).Warn(tt.args...)
+			logger.With(context...).Error(tt.args...)
+			logger.With(context...).DPanic(tt.args...)
+
+			expected := make([]observer.LoggedEntry, 5)
+			for i, lvl := range []zapcore.Level{DebugLevel, InfoLevel, WarnLevel, ErrorLevel, DPanicLevel} {
+				expected[i] = observer.LoggedEntry{
+					Entry:   zapcore.Entry{Message: tt.expect, Level: lvl},
+					Context: expectedFields,
+				}
+			}
+			assert.Equal(t, expected, logs.AllUntimed(), "Unexpected log output.")
+		})
+	}
+}
+
+func TestSugarTemplatedLogging(t *testing.T) {
+	tests := []struct {
+		format string
+		args   []interface{}
+		expect string
+	}{
+		{"", nil, ""},
+		{"foo", nil, "foo"},
+		// If the user fails to pass a template, degrade to fmt.Sprint.
+		{"", []interface{}{"foo"}, "foo"},
+	}
+
+	// Common to all test cases.
+	context := []interface{}{"foo", "bar"}
+	expectedFields := []zapcore.Field{String("foo", "bar")}
+
+	for _, tt := range tests {
+		withSugar(t, DebugLevel, nil, func(logger *SugaredLogger, logs *observer.ObservedLogs) {
+			logger.With(context...).Debugf(tt.format, tt.args...)
+			logger.With(context...).Infof(tt.format, tt.args...)
+			logger.With(context...).Warnf(tt.format, tt.args...)
+			logger.With(context...).Errorf(tt.format, tt.args...)
+			logger.With(context...).DPanicf(tt.format, tt.args...)
+
+			expected := make([]observer.LoggedEntry, 5)
+			for i, lvl := range []zapcore.Level{DebugLevel, InfoLevel, WarnLevel, ErrorLevel, DPanicLevel} {
+				expected[i] = observer.LoggedEntry{
+					Entry:   zapcore.Entry{Message: tt.expect, Level: lvl},
+					Context: expectedFields,
+				}
+			}
+			assert.Equal(t, expected, logs.AllUntimed(), "Unexpected log output.")
+		})
+	}
+}
+
+func TestSugarPanicLogging(t *testing.T) {
+	tests := []struct {
+		loggerLevel zapcore.Level
+		f           func(*SugaredLogger)
+		expectedMsg string
+	}{
+		{FatalLevel, func(s *SugaredLogger) { s.Panic("foo") }, ""},
+		{PanicLevel, func(s *SugaredLogger) { s.Panic("foo") }, "foo"},
+		{DebugLevel, func(s *SugaredLogger) { s.Panic("foo") }, "foo"},
+		{FatalLevel, func(s *SugaredLogger) { s.Panicf("%s", "foo") }, ""},
+		{PanicLevel, func(s *SugaredLogger) { s.Panicf("%s", "foo") }, "foo"},
+		{DebugLevel, func(s *SugaredLogger) { s.Panicf("%s", "foo") }, "foo"},
+		{FatalLevel, func(s *SugaredLogger) { s.Panicw("foo") }, ""},
+		{PanicLevel, func(s *SugaredLogger) { s.Panicw("foo") }, "foo"},
+		{DebugLevel, func(s *SugaredLogger) { s.Panicw("foo") }, "foo"},
+	}
+
+	for _, tt := range tests {
+		withSugar(t, tt.loggerLevel, nil, func(sugar *SugaredLogger, logs *observer.ObservedLogs) {
+			assert.Panics(t, func() { tt.f(sugar) }, "Expected panic-level logger calls to panic.")
+			if tt.expectedMsg != "" {
+				assert.Equal(t, []observer.LoggedEntry{{
+					Context: []zapcore.Field{},
+					Entry:   zapcore.Entry{Message: tt.expectedMsg, Level: PanicLevel},
+				}}, logs.AllUntimed(), "Unexpected log output.")
+			} else {
+				assert.Equal(t, 0, logs.Len(), "Didn't expect any log output.")
+			}
+		})
+	}
+}
+
+func TestSugarFatalLogging(t *testing.T) {
+	tests := []struct {
+		loggerLevel zapcore.Level
+		f           func(*SugaredLogger)
+		expectedMsg string
+	}{
+		{FatalLevel + 1, func(s *SugaredLogger) { s.Fatal("foo") }, ""},
+		{FatalLevel, func(s *SugaredLogger) { s.Fatal("foo") }, "foo"},
+		{DebugLevel, func(s *SugaredLogger) { s.Fatal("foo") }, "foo"},
+		{FatalLevel + 1, func(s *SugaredLogger) { s.Fatalf("%s", "foo") }, ""},
+		{FatalLevel, func(s *SugaredLogger) { s.Fatalf("%s", "foo") }, "foo"},
+		{DebugLevel, func(s *SugaredLogger) { s.Fatalf("%s", "foo") }, "foo"},
+		{FatalLevel + 1, func(s *SugaredLogger) { s.Fatalw("foo") }, ""},
+		{FatalLevel, func(s *SugaredLogger) { s.Fatalw("foo") }, "foo"},
+		{DebugLevel, func(s *SugaredLogger) { s.Fatalw("foo") }, "foo"},
+	}
+
+	for _, tt := range tests {
+		withSugar(t, tt.loggerLevel, nil, func(sugar *SugaredLogger, logs *observer.ObservedLogs) {
+			stub := exit.WithStub(func() { tt.f(sugar) })
+			assert.True(t, stub.Exited, "Expected all calls to fatal logger methods to exit process.")
+			if tt.expectedMsg != "" {
+				assert.Equal(t, []observer.LoggedEntry{{
+					Context: []zapcore.Field{},
+					Entry:   zapcore.Entry{Message: tt.expectedMsg, Level: FatalLevel},
+				}}, logs.AllUntimed(), "Unexpected log output.")
+			} else {
+				assert.Equal(t, 0, logs.Len(), "Didn't expect any log output.")
+			}
+		})
+	}
+}
+
+func TestSugarAddCaller(t *testing.T) {
+	tests := []struct {
+		options []Option
+		pat     string
+	}{
+		{opts(AddCaller()), `.+/sugar_test.go:[\d]+$`},
+		{opts(AddCaller(), AddCallerSkip(1), AddCallerSkip(-1)), `.+/zap/sugar_test.go:[\d]+$`},
+		{opts(AddCaller(), AddCallerSkip(1)), `.+/zap/common_test.go:[\d]+$`},
+		{opts(AddCaller(), AddCallerSkip(1), AddCallerSkip(5)), `.+/src/runtime/.*:[\d]+$`},
+	}
+	for _, tt := range tests {
+		withSugar(t, DebugLevel, tt.options, func(logger *SugaredLogger, logs *observer.ObservedLogs) {
+			logger.Info("")
+			output := logs.AllUntimed()
+			assert.Equal(t, 1, len(output), "Unexpected number of logs written out.")
+			assert.Regexp(
+				t,
+				tt.pat,
+				output[0].Entry.Caller,
+				"Expected to find package name and file name in output.",
+			)
+		})
+	}
+}
+
+func TestSugarAddCallerFail(t *testing.T) {
+	errBuf := &zaptest.Buffer{}
+	withSugar(t, DebugLevel, opts(AddCaller(), AddCallerSkip(1e3), ErrorOutput(errBuf)), func(log *SugaredLogger, logs *observer.ObservedLogs) {
+		log.Info("Failure.")
+		assert.Regexp(
+			t,
+			`Logger.check error: failed to get caller`,
+			errBuf.String(),
+			"Didn't find expected failure message.",
+		)
+		assert.Equal(
+			t,
+			logs.AllUntimed()[0].Entry.Message,
+			"Failure.",
+			"Expected original message to survive failures in runtime.Caller.")
+	})
+}
diff --git a/vendor/go.uber.org/zap/time.go b/vendor/go.uber.org/zap/time.go
new file mode 100644
index 0000000..c5a1f16
--- /dev/null
+++ b/vendor/go.uber.org/zap/time.go
@@ -0,0 +1,27 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import "time"
+
+func timeToMillis(t time.Time) int64 {
+	return t.UnixNano() / int64(time.Millisecond)
+}
diff --git a/vendor/go.uber.org/zap/time_test.go b/vendor/go.uber.org/zap/time_test.go
new file mode 100644
index 0000000..cb993ab
--- /dev/null
+++ b/vendor/go.uber.org/zap/time_test.go
@@ -0,0 +1,42 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTimeToMillis(t *testing.T) {
+	tests := []struct {
+		t     time.Time
+		stamp int64
+	}{
+		{t: time.Unix(0, 0), stamp: 0},
+		{t: time.Unix(1, 0), stamp: 1000},
+		{t: time.Unix(1, int64(500*time.Millisecond)), stamp: 1500},
+	}
+	for _, tt := range tests {
+		assert.Equal(t, tt.stamp, timeToMillis(tt.t), "Unexpected timestamp for time %v.", tt.t)
+	}
+}
diff --git a/vendor/go.uber.org/zap/writer.go b/vendor/go.uber.org/zap/writer.go
new file mode 100644
index 0000000..16f55ce
--- /dev/null
+++ b/vendor/go.uber.org/zap/writer.go
@@ -0,0 +1,96 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"io/ioutil"
+	"os"
+
+	"go.uber.org/zap/zapcore"
+
+	"go.uber.org/multierr"
+)
+
+// Open is a high-level wrapper that takes a variadic number of paths, opens or
+// creates each of the specified files, and combines them into a locked
+// WriteSyncer. It also returns any error encountered and a function to close
+// any opened files.
+//
+// Passing no paths returns a no-op WriteSyncer. The special paths "stdout" and
+// "stderr" are interpreted as os.Stdout and os.Stderr, respectively.
+func Open(paths ...string) (zapcore.WriteSyncer, func(), error) {
+	writers, close, err := open(paths)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	writer := CombineWriteSyncers(writers...)
+	return writer, close, nil
+}
+
+func open(paths []string) ([]zapcore.WriteSyncer, func(), error) {
+	var openErr error
+	writers := make([]zapcore.WriteSyncer, 0, len(paths))
+	files := make([]*os.File, 0, len(paths))
+	close := func() {
+		for _, f := range files {
+			f.Close()
+		}
+	}
+	for _, path := range paths {
+		switch path {
+		case "stdout":
+			writers = append(writers, os.Stdout)
+			// Don't close standard out.
+			continue
+		case "stderr":
+			writers = append(writers, os.Stderr)
+			// Don't close standard error.
+			continue
+		}
+		f, err := os.OpenFile(path, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0644)
+		openErr = multierr.Append(openErr, err)
+		if err == nil {
+			writers = append(writers, f)
+			files = append(files, f)
+		}
+	}
+
+	if openErr != nil {
+		close()
+		return writers, nil, openErr
+	}
+
+	return writers, close, nil
+}
+
+// CombineWriteSyncers is a utility that combines multiple WriteSyncers into a
+// single, locked WriteSyncer. If no inputs are supplied, it returns a no-op
+// WriteSyncer.
+//
+// It's provided purely as a convenience; the result is no different from
+// using zapcore.NewMultiWriteSyncer and zapcore.Lock individually.
+func CombineWriteSyncers(writers ...zapcore.WriteSyncer) zapcore.WriteSyncer {
+	if len(writers) == 0 {
+		return zapcore.AddSync(ioutil.Discard)
+	}
+	return zapcore.Lock(zapcore.NewMultiWriteSyncer(writers...))
+}
diff --git a/vendor/go.uber.org/zap/writer_test.go b/vendor/go.uber.org/zap/writer_test.go
new file mode 100644
index 0000000..1293832
--- /dev/null
+++ b/vendor/go.uber.org/zap/writer_test.go
@@ -0,0 +1,125 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/zap/zapcore"
+)
+
+func TestOpenNoPaths(t *testing.T) {
+	ws, cleanup, err := Open()
+	defer cleanup()
+
+	assert.NoError(t, err, "Expected opening no paths to succeed.")
+	assert.Equal(
+		t,
+		zapcore.AddSync(ioutil.Discard),
+		ws,
+		"Expected opening no paths to return a no-op WriteSyncer.",
+	)
+}
+
+func TestOpen(t *testing.T) {
+	temp, err := ioutil.TempFile("", "zap-open-test")
+	require.NoError(t, err, "Couldn't create a temporary file for test.")
+	defer os.Remove(temp.Name())
+
+	tests := []struct {
+		paths     []string
+		filenames []string
+		error     string
+	}{
+		{[]string{"stdout"}, []string{os.Stdout.Name()}, ""},
+		{[]string{"stderr"}, []string{os.Stderr.Name()}, ""},
+		{[]string{temp.Name()}, []string{temp.Name()}, ""},
+		{[]string{"/foo/bar/baz"}, []string{}, "open /foo/bar/baz: no such file or directory"},
+		{
+			paths:     []string{"stdout", "/foo/bar/baz", temp.Name(), "/baz/quux"},
+			filenames: []string{os.Stdout.Name(), temp.Name()},
+			error:     "open /foo/bar/baz: no such file or directory; open /baz/quux: no such file or directory",
+		},
+	}
+
+	for _, tt := range tests {
+		wss, cleanup, err := open(tt.paths)
+		if err == nil {
+			defer cleanup()
+		}
+
+		if tt.error == "" {
+			assert.NoError(t, err, "Unexpected error opening paths %v.", tt.paths)
+		} else {
+			assert.Equal(t, tt.error, err.Error(), "Unexpected error opening paths %v.", tt.paths)
+		}
+		names := make([]string, len(wss))
+		for i, ws := range wss {
+			f, ok := ws.(*os.File)
+			require.True(t, ok, "Expected all WriteSyncers returned from open() to be files.")
+			names[i] = f.Name()
+		}
+		assert.Equal(t, tt.filenames, names, "Opened unexpected files given paths %v.", tt.paths)
+	}
+}
+
+func TestOpenFails(t *testing.T) {
+	tests := []struct {
+		paths []string
+	}{
+		{
+			paths: []string{"./non-existent-dir/file"},
+		},
+		{
+			paths: []string{"stdout", "./non-existent-dir/file"},
+		},
+	}
+
+	for _, tt := range tests {
+		_, cleanup, err := Open(tt.paths...)
+		require.Nil(t, cleanup, "Cleanup function should never be nil")
+		assert.Error(t, err, "Open with non-existent directory should fail")
+	}
+}
+
+type testWriter struct {
+	expected string
+	t        testing.TB
+}
+
+func (w *testWriter) Write(actual []byte) (int, error) {
+	assert.Equal(w.t, []byte(w.expected), actual, "Unexpected write error.")
+	return len(actual), nil
+}
+
+func (w *testWriter) Sync() error {
+	return nil
+}
+
+func TestCombineWriteSyncers(t *testing.T) {
+	tw := &testWriter{"test", t}
+	w := CombineWriteSyncers(tw)
+	w.Write([]byte("test"))
+}
diff --git a/vendor/go.uber.org/zap/zapcore/console_encoder.go b/vendor/go.uber.org/zap/zapcore/console_encoder.go
new file mode 100644
index 0000000..b787596
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/console_encoder.go
@@ -0,0 +1,147 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"fmt"
+	"sync"
+
+	"go.uber.org/zap/buffer"
+	"go.uber.org/zap/internal/bufferpool"
+)
+
+var _sliceEncoderPool = sync.Pool{
+	New: func() interface{} {
+		return &sliceArrayEncoder{elems: make([]interface{}, 0, 2)}
+	},
+}
+
+func getSliceEncoder() *sliceArrayEncoder {
+	return _sliceEncoderPool.Get().(*sliceArrayEncoder)
+}
+
+func putSliceEncoder(e *sliceArrayEncoder) {
+	e.elems = e.elems[:0]
+	_sliceEncoderPool.Put(e)
+}
+
+type consoleEncoder struct {
+	*jsonEncoder
+}
+
+// NewConsoleEncoder creates an encoder whose output is designed for human -
+// rather than machine - consumption. It serializes the core log entry data
+// (message, level, timestamp, etc.) in a plain-text format and leaves the
+// structured context as JSON.
+//
+// Note that although the console encoder doesn't use the keys specified in the
+// encoder configuration, it will omit any element whose key is set to the empty
+// string.
+func NewConsoleEncoder(cfg EncoderConfig) Encoder {
+	return consoleEncoder{newJSONEncoder(cfg, true)}
+}
+
+func (c consoleEncoder) Clone() Encoder {
+	return consoleEncoder{c.jsonEncoder.Clone().(*jsonEncoder)}
+}
+
+func (c consoleEncoder) EncodeEntry(ent Entry, fields []Field) (*buffer.Buffer, error) {
+	line := bufferpool.Get()
+
+	// We don't want the entry's metadata to be quoted and escaped (if it's
+	// encoded as strings), which means that we can't use the JSON encoder. The
+	// simplest option is to use the memory encoder and fmt.Fprint.
+	//
+	// If this ever becomes a performance bottleneck, we can implement
+	// ArrayEncoder for our plain-text format.
+	arr := getSliceEncoder()
+	if c.TimeKey != "" && c.EncodeTime != nil {
+		c.EncodeTime(ent.Time, arr)
+	}
+	if c.LevelKey != "" && c.EncodeLevel != nil {
+		c.EncodeLevel(ent.Level, arr)
+	}
+	if ent.LoggerName != "" && c.NameKey != "" {
+		nameEncoder := c.EncodeName
+
+		if nameEncoder == nil {
+			// Fall back to FullNameEncoder for backward compatibility.
+			nameEncoder = FullNameEncoder
+		}
+
+		nameEncoder(ent.LoggerName, arr)
+	}
+	if ent.Caller.Defined && c.CallerKey != "" && c.EncodeCaller != nil {
+		c.EncodeCaller(ent.Caller, arr)
+	}
+	for i := range arr.elems {
+		if i > 0 {
+			line.AppendByte('\t')
+		}
+		fmt.Fprint(line, arr.elems[i])
+	}
+	putSliceEncoder(arr)
+
+	// Add the message itself.
+	if c.MessageKey != "" {
+		c.addTabIfNecessary(line)
+		line.AppendString(ent.Message)
+	}
+
+	// Add any structured context.
+	c.writeContext(line, fields)
+
+	// If there's no stacktrace key, honor that; this allows users to force
+	// single-line output.
+	if ent.Stack != "" && c.StacktraceKey != "" {
+		line.AppendByte('\n')
+		line.AppendString(ent.Stack)
+	}
+
+	if c.LineEnding != "" {
+		line.AppendString(c.LineEnding)
+	} else {
+		line.AppendString(DefaultLineEnding)
+	}
+	return line, nil
+}
+
+func (c consoleEncoder) writeContext(line *buffer.Buffer, extra []Field) {
+	context := c.jsonEncoder.Clone().(*jsonEncoder)
+	defer context.buf.Free()
+
+	addFields(context, extra)
+	context.closeOpenNamespaces()
+	if context.buf.Len() == 0 {
+		return
+	}
+
+	c.addTabIfNecessary(line)
+	line.AppendByte('{')
+	line.Write(context.buf.Bytes())
+	line.AppendByte('}')
+}
+
+func (c consoleEncoder) addTabIfNecessary(line *buffer.Buffer) {
+	if line.Len() > 0 {
+		line.AppendByte('\t')
+	}
+}
diff --git a/vendor/go.uber.org/zap/zapcore/console_encoder_bench_test.go b/vendor/go.uber.org/zap/zapcore/console_encoder_bench_test.go
new file mode 100644
index 0000000..62feaea
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/console_encoder_bench_test.go
@@ -0,0 +1,49 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore_test
+
+import (
+	"testing"
+
+	. "go.uber.org/zap/zapcore"
+)
+
+func BenchmarkZapConsole(b *testing.B) {
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			enc := NewConsoleEncoder(humanEncoderConfig())
+			enc.AddString("str", "foo")
+			enc.AddInt64("int64-1", 1)
+			enc.AddInt64("int64-2", 2)
+			enc.AddFloat64("float64", 1.0)
+			enc.AddString("string1", "\n")
+			enc.AddString("string2", "💩")
+			enc.AddString("string3", "🤔")
+			enc.AddString("string4", "🙊")
+			enc.AddBool("bool", true)
+			buf, _ := enc.EncodeEntry(Entry{
+				Message: "fake",
+				Level:   DebugLevel,
+			}, nil)
+			buf.Free()
+		}
+	})
+}
diff --git a/vendor/go.uber.org/zap/zapcore/core.go b/vendor/go.uber.org/zap/zapcore/core.go
new file mode 100644
index 0000000..a1ef8b0
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/core.go
@@ -0,0 +1,113 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+// Core is a minimal, fast logger interface. It's designed for library authors
+// to wrap in a more user-friendly API.
+type Core interface {
+	LevelEnabler
+
+	// With adds structured context to the Core.
+	With([]Field) Core
+	// Check determines whether the supplied Entry should be logged (using the
+	// embedded LevelEnabler and possibly some extra logic). If the entry
+	// should be logged, the Core adds itself to the CheckedEntry and returns
+	// the result.
+	//
+	// Callers must use Check before calling Write.
+	Check(Entry, *CheckedEntry) *CheckedEntry
+	// Write serializes the Entry and any Fields supplied at the log site and
+	// writes them to their destination.
+	//
+	// If called, Write should always log the Entry and Fields; it should not
+	// replicate the logic of Check.
+	Write(Entry, []Field) error
+	// Sync flushes buffered logs (if any).
+	Sync() error
+}
+
+type nopCore struct{}
+
+// NewNopCore returns a no-op Core.
+func NewNopCore() Core                                        { return nopCore{} }
+func (nopCore) Enabled(Level) bool                            { return false }
+func (n nopCore) With([]Field) Core                           { return n }
+func (nopCore) Check(_ Entry, ce *CheckedEntry) *CheckedEntry { return ce }
+func (nopCore) Write(Entry, []Field) error                    { return nil }
+func (nopCore) Sync() error                                   { return nil }
+
+// NewCore creates a Core that writes logs to a WriteSyncer.
+func NewCore(enc Encoder, ws WriteSyncer, enab LevelEnabler) Core {
+	return &ioCore{
+		LevelEnabler: enab,
+		enc:          enc,
+		out:          ws,
+	}
+}
+
+type ioCore struct {
+	LevelEnabler
+	enc Encoder
+	out WriteSyncer
+}
+
+func (c *ioCore) With(fields []Field) Core {
+	clone := c.clone()
+	addFields(clone.enc, fields)
+	return clone
+}
+
+func (c *ioCore) Check(ent Entry, ce *CheckedEntry) *CheckedEntry {
+	if c.Enabled(ent.Level) {
+		return ce.AddCore(ent, c)
+	}
+	return ce
+}
+
+func (c *ioCore) Write(ent Entry, fields []Field) error {
+	buf, err := c.enc.EncodeEntry(ent, fields)
+	if err != nil {
+		return err
+	}
+	_, err = c.out.Write(buf.Bytes())
+	buf.Free()
+	if err != nil {
+		return err
+	}
+	if ent.Level > ErrorLevel {
+		// Since we may be crashing the program, sync the output. Ignore Sync
+		// errors, pending a clean solution to issue #370.
+		c.Sync()
+	}
+	return nil
+}
+
+func (c *ioCore) Sync() error {
+	return c.out.Sync()
+}
+
+func (c *ioCore) clone() *ioCore {
+	return &ioCore{
+		LevelEnabler: c.LevelEnabler,
+		enc:          c.enc.Clone(),
+		out:          c.out,
+	}
+}
diff --git a/vendor/go.uber.org/zap/zapcore/core_test.go b/vendor/go.uber.org/zap/zapcore/core_test.go
new file mode 100644
index 0000000..20a4720
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/core_test.go
@@ -0,0 +1,163 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore_test
+
+import (
+	"errors"
+	"io/ioutil"
+	"os"
+	"testing"
+	"time"
+
+	. "go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func makeInt64Field(key string, val int) Field {
+	return Field{Type: Int64Type, Integer: int64(val), Key: key}
+}
+
+func TestNopCore(t *testing.T) {
+	entry := Entry{
+		Message:    "test",
+		Level:      InfoLevel,
+		Time:       time.Now(),
+		LoggerName: "main",
+		Stack:      "fake-stack",
+	}
+	ce := &CheckedEntry{}
+
+	allLevels := []Level{
+		DebugLevel,
+		InfoLevel,
+		WarnLevel,
+		ErrorLevel,
+		DPanicLevel,
+		PanicLevel,
+		FatalLevel,
+	}
+	core := NewNopCore()
+	assert.Equal(t, core, core.With([]Field{makeInt64Field("k", 42)}), "Expected no-op With.")
+	for _, level := range allLevels {
+		assert.False(t, core.Enabled(level), "Expected all levels to be disabled in no-op core.")
+		assert.Equal(t, ce, core.Check(entry, ce), "Expected no-op Check to return checked entry unchanged.")
+		assert.NoError(t, core.Write(entry, nil), "Expected no-op Writes to always succeed.")
+		assert.NoError(t, core.Sync(), "Expected no-op Syncs to always succeed.")
+	}
+}
+
+func TestIOCore(t *testing.T) {
+	temp, err := ioutil.TempFile("", "zapcore-test-iocore")
+	require.NoError(t, err, "Failed to create temp file.")
+	defer os.Remove(temp.Name())
+
+	// Drop timestamps for simpler assertions (timestamp encoding is tested
+	// elsewhere).
+	cfg := testEncoderConfig()
+	cfg.TimeKey = ""
+
+	core := NewCore(
+		NewJSONEncoder(cfg),
+		temp,
+		InfoLevel,
+	).With([]Field{makeInt64Field("k", 1)})
+	defer assert.NoError(t, core.Sync(), "Expected Syncing a temp file to succeed.")
+
+	if ce := core.Check(Entry{Level: DebugLevel, Message: "debug"}, nil); ce != nil {
+		ce.Write(makeInt64Field("k", 2))
+	}
+	if ce := core.Check(Entry{Level: InfoLevel, Message: "info"}, nil); ce != nil {
+		ce.Write(makeInt64Field("k", 3))
+	}
+	if ce := core.Check(Entry{Level: WarnLevel, Message: "warn"}, nil); ce != nil {
+		ce.Write(makeInt64Field("k", 4))
+	}
+
+	logged, err := ioutil.ReadFile(temp.Name())
+	require.NoError(t, err, "Failed to read from temp file.")
+	require.Equal(
+		t,
+		`{"level":"info","msg":"info","k":1,"k":3}`+"\n"+
+			`{"level":"warn","msg":"warn","k":1,"k":4}`+"\n",
+		string(logged),
+		"Unexpected log output.",
+	)
+}
+
+func TestIOCoreSyncFail(t *testing.T) {
+	sink := &zaptest.Discarder{}
+	err := errors.New("failed")
+	sink.SetError(err)
+
+	core := NewCore(
+		NewJSONEncoder(testEncoderConfig()),
+		sink,
+		DebugLevel,
+	)
+
+	assert.Equal(
+		t,
+		err,
+		core.Sync(),
+		"Expected core.Sync to return errors from underlying WriteSyncer.",
+	)
+}
+
+func TestIOCoreSyncsOutput(t *testing.T) {
+	tests := []struct {
+		entry      Entry
+		shouldSync bool
+	}{
+		{Entry{Level: DebugLevel}, false},
+		{Entry{Level: InfoLevel}, false},
+		{Entry{Level: WarnLevel}, false},
+		{Entry{Level: ErrorLevel}, false},
+		{Entry{Level: DPanicLevel}, true},
+		{Entry{Level: PanicLevel}, true},
+		{Entry{Level: FatalLevel}, true},
+	}
+
+	for _, tt := range tests {
+		sink := &zaptest.Discarder{}
+		core := NewCore(
+			NewJSONEncoder(testEncoderConfig()),
+			sink,
+			DebugLevel,
+		)
+
+		core.Write(tt.entry, nil)
+		assert.Equal(t, tt.shouldSync, sink.Called(), "Incorrect Sync behavior.")
+	}
+}
+
+func TestIOCoreWriteFailure(t *testing.T) {
+	core := NewCore(
+		NewJSONEncoder(testEncoderConfig()),
+		Lock(&zaptest.FailWriter{}),
+		DebugLevel,
+	)
+	err := core.Write(Entry{}, nil)
+	// Should log the error.
+	assert.Error(t, err, "Expected writing Entry to fail.")
+}
diff --git a/vendor/go.uber.org/zap/zapcore/doc.go b/vendor/go.uber.org/zap/zapcore/doc.go
new file mode 100644
index 0000000..31000e9
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/doc.go
@@ -0,0 +1,24 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Package zapcore defines and implements the low-level interfaces upon which
+// zap is built. By providing alternate implementations of these interfaces,
+// external packages can extend zap's capabilities.
+package zapcore // import "go.uber.org/zap/zapcore"
diff --git a/vendor/go.uber.org/zap/zapcore/encoder.go b/vendor/go.uber.org/zap/zapcore/encoder.go
new file mode 100644
index 0000000..f050952
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/encoder.go
@@ -0,0 +1,348 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"time"
+
+	"go.uber.org/zap/buffer"
+)
+
+// DefaultLineEnding defines the default line ending when writing logs.
+// Alternate line endings specified in EncoderConfig can override this
+// behavior.
+const DefaultLineEnding = "\n"
+
+// A LevelEncoder serializes a Level to a primitive type.
+type LevelEncoder func(Level, PrimitiveArrayEncoder)
+
+// LowercaseLevelEncoder serializes a Level to a lowercase string. For example,
+// InfoLevel is serialized to "info".
+func LowercaseLevelEncoder(l Level, enc PrimitiveArrayEncoder) {
+	enc.AppendString(l.String())
+}
+
+// LowercaseColorLevelEncoder serializes a Level to a lowercase string and adds coloring.
+// For example, InfoLevel is serialized to "info" and colored blue.
+func LowercaseColorLevelEncoder(l Level, enc PrimitiveArrayEncoder) {
+	s, ok := _levelToLowercaseColorString[l]
+	if !ok {
+		s = _unknownLevelColor.Add(l.String())
+	}
+	enc.AppendString(s)
+}
+
+// CapitalLevelEncoder serializes a Level to an all-caps string. For example,
+// InfoLevel is serialized to "INFO".
+func CapitalLevelEncoder(l Level, enc PrimitiveArrayEncoder) {
+	enc.AppendString(l.CapitalString())
+}
+
+// CapitalColorLevelEncoder serializes a Level to an all-caps string and adds color.
+// For example, InfoLevel is serialized to "INFO" and colored blue.
+func CapitalColorLevelEncoder(l Level, enc PrimitiveArrayEncoder) {
+	s, ok := _levelToCapitalColorString[l]
+	if !ok {
+		s = _unknownLevelColor.Add(l.CapitalString())
+	}
+	enc.AppendString(s)
+}
+
+// UnmarshalText unmarshals text to a LevelEncoder. "capital" is unmarshaled to
+// CapitalLevelEncoder, "coloredCapital" is unmarshaled to CapitalColorLevelEncoder,
+// "colored" is unmarshaled to LowercaseColorLevelEncoder, and anything else
+// is unmarshaled to LowercaseLevelEncoder.
+func (e *LevelEncoder) UnmarshalText(text []byte) error {
+	switch string(text) {
+	case "capital":
+		*e = CapitalLevelEncoder
+	case "capitalColor":
+		*e = CapitalColorLevelEncoder
+	case "color":
+		*e = LowercaseColorLevelEncoder
+	default:
+		*e = LowercaseLevelEncoder
+	}
+	return nil
+}
+
+// A TimeEncoder serializes a time.Time to a primitive type.
+type TimeEncoder func(time.Time, PrimitiveArrayEncoder)
+
+// EpochTimeEncoder serializes a time.Time to a floating-point number of seconds
+// since the Unix epoch.
+func EpochTimeEncoder(t time.Time, enc PrimitiveArrayEncoder) {
+	nanos := t.UnixNano()
+	sec := float64(nanos) / float64(time.Second)
+	enc.AppendFloat64(sec)
+}
+
+// EpochMillisTimeEncoder serializes a time.Time to a floating-point number of
+// milliseconds since the Unix epoch.
+func EpochMillisTimeEncoder(t time.Time, enc PrimitiveArrayEncoder) {
+	nanos := t.UnixNano()
+	millis := float64(nanos) / float64(time.Millisecond)
+	enc.AppendFloat64(millis)
+}
+
+// EpochNanosTimeEncoder serializes a time.Time to an integer number of
+// nanoseconds since the Unix epoch.
+func EpochNanosTimeEncoder(t time.Time, enc PrimitiveArrayEncoder) {
+	enc.AppendInt64(t.UnixNano())
+}
+
+// ISO8601TimeEncoder serializes a time.Time to an ISO8601-formatted string
+// with millisecond precision.
+func ISO8601TimeEncoder(t time.Time, enc PrimitiveArrayEncoder) {
+	enc.AppendString(t.Format("2006-01-02T15:04:05.000Z0700"))
+}
+
+// UnmarshalText unmarshals text to a TimeEncoder. "iso8601" and "ISO8601" are
+// unmarshaled to ISO8601TimeEncoder, "millis" is unmarshaled to
+// EpochMillisTimeEncoder, and anything else is unmarshaled to EpochTimeEncoder.
+func (e *TimeEncoder) UnmarshalText(text []byte) error {
+	switch string(text) {
+	case "iso8601", "ISO8601":
+		*e = ISO8601TimeEncoder
+	case "millis":
+		*e = EpochMillisTimeEncoder
+	case "nanos":
+		*e = EpochNanosTimeEncoder
+	default:
+		*e = EpochTimeEncoder
+	}
+	return nil
+}
+
+// A DurationEncoder serializes a time.Duration to a primitive type.
+type DurationEncoder func(time.Duration, PrimitiveArrayEncoder)
+
+// SecondsDurationEncoder serializes a time.Duration to a floating-point number of seconds elapsed.
+func SecondsDurationEncoder(d time.Duration, enc PrimitiveArrayEncoder) {
+	enc.AppendFloat64(float64(d) / float64(time.Second))
+}
+
+// NanosDurationEncoder serializes a time.Duration to an integer number of
+// nanoseconds elapsed.
+func NanosDurationEncoder(d time.Duration, enc PrimitiveArrayEncoder) {
+	enc.AppendInt64(int64(d))
+}
+
+// StringDurationEncoder serializes a time.Duration using its built-in String
+// method.
+func StringDurationEncoder(d time.Duration, enc PrimitiveArrayEncoder) {
+	enc.AppendString(d.String())
+}
+
+// UnmarshalText unmarshals text to a DurationEncoder. "string" is unmarshaled
+// to StringDurationEncoder, and anything else is unmarshaled to
+// NanosDurationEncoder.
+func (e *DurationEncoder) UnmarshalText(text []byte) error {
+	switch string(text) {
+	case "string":
+		*e = StringDurationEncoder
+	case "nanos":
+		*e = NanosDurationEncoder
+	default:
+		*e = SecondsDurationEncoder
+	}
+	return nil
+}
+
+// A CallerEncoder serializes an EntryCaller to a primitive type.
+type CallerEncoder func(EntryCaller, PrimitiveArrayEncoder)
+
+// FullCallerEncoder serializes a caller in /full/path/to/package/file:line
+// format.
+func FullCallerEncoder(caller EntryCaller, enc PrimitiveArrayEncoder) {
+	// TODO: consider using a byte-oriented API to save an allocation.
+	enc.AppendString(caller.String())
+}
+
+// ShortCallerEncoder serializes a caller in package/file:line format, trimming
+// all but the final directory from the full path.
+func ShortCallerEncoder(caller EntryCaller, enc PrimitiveArrayEncoder) {
+	// TODO: consider using a byte-oriented API to save an allocation.
+	enc.AppendString(caller.TrimmedPath())
+}
+
+// UnmarshalText unmarshals text to a CallerEncoder. "full" is unmarshaled to
+// FullCallerEncoder and anything else is unmarshaled to ShortCallerEncoder.
+func (e *CallerEncoder) UnmarshalText(text []byte) error {
+	switch string(text) {
+	case "full":
+		*e = FullCallerEncoder
+	default:
+		*e = ShortCallerEncoder
+	}
+	return nil
+}
+
+// A NameEncoder serializes a period-separated logger name to a primitive
+// type.
+type NameEncoder func(string, PrimitiveArrayEncoder)
+
+// FullNameEncoder serializes the logger name as-is.
+func FullNameEncoder(loggerName string, enc PrimitiveArrayEncoder) {
+	enc.AppendString(loggerName)
+}
+
+// UnmarshalText unmarshals text to a NameEncoder. Currently, everything is
+// unmarshaled to FullNameEncoder.
+func (e *NameEncoder) UnmarshalText(text []byte) error {
+	switch string(text) {
+	case "full":
+		*e = FullNameEncoder
+	default:
+		*e = FullNameEncoder
+	}
+	return nil
+}
+
+// An EncoderConfig allows users to configure the concrete encoders supplied by
+// zapcore.
+type EncoderConfig struct {
+	// Set the keys used for each log entry. If any key is empty, that portion
+	// of the entry is omitted.
+	MessageKey    string `json:"messageKey" yaml:"messageKey"`
+	LevelKey      string `json:"levelKey" yaml:"levelKey"`
+	TimeKey       string `json:"timeKey" yaml:"timeKey"`
+	NameKey       string `json:"nameKey" yaml:"nameKey"`
+	CallerKey     string `json:"callerKey" yaml:"callerKey"`
+	StacktraceKey string `json:"stacktraceKey" yaml:"stacktraceKey"`
+	LineEnding    string `json:"lineEnding" yaml:"lineEnding"`
+	// Configure the primitive representations of common complex types. For
+	// example, some users may want all time.Times serialized as floating-point
+	// seconds since epoch, while others may prefer ISO8601 strings.
+	EncodeLevel    LevelEncoder    `json:"levelEncoder" yaml:"levelEncoder"`
+	EncodeTime     TimeEncoder     `json:"timeEncoder" yaml:"timeEncoder"`
+	EncodeDuration DurationEncoder `json:"durationEncoder" yaml:"durationEncoder"`
+	EncodeCaller   CallerEncoder   `json:"callerEncoder" yaml:"callerEncoder"`
+	// Unlike the other primitive type encoders, EncodeName is optional. The
+	// zero value falls back to FullNameEncoder.
+	EncodeName NameEncoder `json:"nameEncoder" yaml:"nameEncoder"`
+}
+
+// ObjectEncoder is a strongly-typed, encoding-agnostic interface for adding a
+// map- or struct-like object to the logging context. Like maps, ObjectEncoders
+// aren't safe for concurrent use (though typical use shouldn't require locks).
+type ObjectEncoder interface {
+	// Logging-specific marshalers.
+	AddArray(key string, marshaler ArrayMarshaler) error
+	AddObject(key string, marshaler ObjectMarshaler) error
+
+	// Built-in types.
+	AddBinary(key string, value []byte)     // for arbitrary bytes
+	AddByteString(key string, value []byte) // for UTF-8 encoded bytes
+	AddBool(key string, value bool)
+	AddComplex128(key string, value complex128)
+	AddComplex64(key string, value complex64)
+	AddDuration(key string, value time.Duration)
+	AddFloat64(key string, value float64)
+	AddFloat32(key string, value float32)
+	AddInt(key string, value int)
+	AddInt64(key string, value int64)
+	AddInt32(key string, value int32)
+	AddInt16(key string, value int16)
+	AddInt8(key string, value int8)
+	AddString(key, value string)
+	AddTime(key string, value time.Time)
+	AddUint(key string, value uint)
+	AddUint64(key string, value uint64)
+	AddUint32(key string, value uint32)
+	AddUint16(key string, value uint16)
+	AddUint8(key string, value uint8)
+	AddUintptr(key string, value uintptr)
+
+	// AddReflected uses reflection to serialize arbitrary objects, so it's slow
+	// and allocation-heavy.
+	AddReflected(key string, value interface{}) error
+	// OpenNamespace opens an isolated namespace where all subsequent fields will
+	// be added. Applications can use namespaces to prevent key collisions when
+	// injecting loggers into sub-components or third-party libraries.
+	OpenNamespace(key string)
+}
+
+// ArrayEncoder is a strongly-typed, encoding-agnostic interface for adding
+// array-like objects to the logging context. Of note, it supports mixed-type
+// arrays even though they aren't typical in Go. Like slices, ArrayEncoders
+// aren't safe for concurrent use (though typical use shouldn't require locks).
+type ArrayEncoder interface {
+	// Built-in types.
+	PrimitiveArrayEncoder
+
+	// Time-related types.
+	AppendDuration(time.Duration)
+	AppendTime(time.Time)
+
+	// Logging-specific marshalers.
+	AppendArray(ArrayMarshaler) error
+	AppendObject(ObjectMarshaler) error
+
+	// AppendReflected uses reflection to serialize arbitrary objects, so it's
+	// slow and allocation-heavy.
+	AppendReflected(value interface{}) error
+}
+
+// PrimitiveArrayEncoder is the subset of the ArrayEncoder interface that deals
+// only in Go's built-in types. It's included only so that Duration- and
+// TimeEncoders cannot trigger infinite recursion.
+type PrimitiveArrayEncoder interface {
+	// Built-in types.
+	AppendBool(bool)
+	AppendByteString([]byte) // for UTF-8 encoded bytes
+	AppendComplex128(complex128)
+	AppendComplex64(complex64)
+	AppendFloat64(float64)
+	AppendFloat32(float32)
+	AppendInt(int)
+	AppendInt64(int64)
+	AppendInt32(int32)
+	AppendInt16(int16)
+	AppendInt8(int8)
+	AppendString(string)
+	AppendUint(uint)
+	AppendUint64(uint64)
+	AppendUint32(uint32)
+	AppendUint16(uint16)
+	AppendUint8(uint8)
+	AppendUintptr(uintptr)
+}
+
+// Encoder is a format-agnostic interface for all log entry marshalers. Since
+// log encoders don't need to support the same wide range of use cases as
+// general-purpose marshalers, it's possible to make them faster and
+// lower-allocation.
+//
+// Implementations of the ObjectEncoder interface's methods can, of course,
+// freely modify the receiver. However, the Clone and EncodeEntry methods will
+// be called concurrently and shouldn't modify the receiver.
+type Encoder interface {
+	ObjectEncoder
+
+	// Clone copies the encoder, ensuring that adding fields to the copy doesn't
+	// affect the original.
+	Clone() Encoder
+
+	// EncodeEntry encodes an entry and fields, along with any accumulated
+	// context, into a byte buffer and returns it.
+	EncodeEntry(Entry, []Field) (*buffer.Buffer, error)
+}
diff --git a/vendor/go.uber.org/zap/zapcore/encoder_test.go b/vendor/go.uber.org/zap/zapcore/encoder_test.go
new file mode 100644
index 0000000..0464167
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/encoder_test.go
@@ -0,0 +1,636 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore_test
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	. "go.uber.org/zap/zapcore"
+)
+
+var (
+	_epoch     = time.Date(1970, time.January, 1, 0, 0, 0, 0, time.UTC)
+	_testEntry = Entry{
+		LoggerName: "main",
+		Level:      InfoLevel,
+		Message:    `hello`,
+		Time:       _epoch,
+		Stack:      "fake-stack",
+		Caller:     EntryCaller{Defined: true, File: "foo.go", Line: 42},
+	}
+)
+
+func testEncoderConfig() EncoderConfig {
+	return EncoderConfig{
+		MessageKey:     "msg",
+		LevelKey:       "level",
+		NameKey:        "name",
+		TimeKey:        "ts",
+		CallerKey:      "caller",
+		StacktraceKey:  "stacktrace",
+		LineEnding:     "\n",
+		EncodeTime:     EpochTimeEncoder,
+		EncodeLevel:    LowercaseLevelEncoder,
+		EncodeDuration: SecondsDurationEncoder,
+		EncodeCaller:   ShortCallerEncoder,
+	}
+}
+
+func humanEncoderConfig() EncoderConfig {
+	cfg := testEncoderConfig()
+	cfg.EncodeTime = ISO8601TimeEncoder
+	cfg.EncodeLevel = CapitalLevelEncoder
+	cfg.EncodeDuration = StringDurationEncoder
+	return cfg
+}
+
+func withJSONEncoder(f func(Encoder)) {
+	f(NewJSONEncoder(testEncoderConfig()))
+}
+
+func withConsoleEncoder(f func(Encoder)) {
+	f(NewConsoleEncoder(humanEncoderConfig()))
+}
+
+func capitalNameEncoder(loggerName string, enc PrimitiveArrayEncoder) {
+	enc.AppendString(strings.ToUpper(loggerName))
+}
+
+func TestEncoderConfiguration(t *testing.T) {
+	base := testEncoderConfig()
+
+	tests := []struct {
+		desc            string
+		cfg             EncoderConfig
+		amendEntry      func(Entry) Entry
+		extra           func(Encoder)
+		expectedJSON    string
+		expectedConsole string
+	}{
+		{
+			desc: "messages to be escaped",
+			cfg:  base,
+			amendEntry: func(ent Entry) Entry {
+				ent.Message = `hello\`
+				return ent
+			},
+			expectedJSON:    `{"level":"info","ts":0,"name":"main","caller":"foo.go:42","msg":"hello\\","stacktrace":"fake-stack"}` + "\n",
+			expectedConsole: "0\tinfo\tmain\tfoo.go:42\thello\\\nfake-stack\n",
+		},
+		{
+			desc: "use custom entry keys in JSON output and ignore them in console output",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+			},
+			expectedJSON:    `{"L":"info","T":0,"N":"main","C":"foo.go:42","M":"hello","S":"fake-stack"}` + "\n",
+			expectedConsole: "0\tinfo\tmain\tfoo.go:42\thello\nfake-stack\n",
+		},
+		{
+			desc: "skip level if LevelKey is omitted",
+			cfg: EncoderConfig{
+				LevelKey:       "",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+			},
+			expectedJSON:    `{"T":0,"N":"main","C":"foo.go:42","M":"hello","S":"fake-stack"}` + "\n",
+			expectedConsole: "0\tmain\tfoo.go:42\thello\nfake-stack\n",
+		},
+		{
+			desc: "skip timestamp if TimeKey is omitted",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+			},
+			expectedJSON:    `{"L":"info","N":"main","C":"foo.go:42","M":"hello","S":"fake-stack"}` + "\n",
+			expectedConsole: "info\tmain\tfoo.go:42\thello\nfake-stack\n",
+		},
+		{
+			desc: "skip message if MessageKey is omitted",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+			},
+			expectedJSON:    `{"L":"info","T":0,"N":"main","C":"foo.go:42","S":"fake-stack"}` + "\n",
+			expectedConsole: "0\tinfo\tmain\tfoo.go:42\nfake-stack\n",
+		},
+		{
+			desc: "skip name if NameKey is omitted",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+			},
+			expectedJSON:    `{"L":"info","T":0,"C":"foo.go:42","M":"hello","S":"fake-stack"}` + "\n",
+			expectedConsole: "0\tinfo\tfoo.go:42\thello\nfake-stack\n",
+		},
+		{
+			desc: "skip caller if CallerKey is omitted",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+			},
+			expectedJSON:    `{"L":"info","T":0,"N":"main","M":"hello","S":"fake-stack"}` + "\n",
+			expectedConsole: "0\tinfo\tmain\thello\nfake-stack\n",
+		},
+		{
+			desc: "skip stacktrace if StacktraceKey is omitted",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+			},
+			expectedJSON:    `{"L":"info","T":0,"N":"main","C":"foo.go:42","M":"hello"}` + "\n",
+			expectedConsole: "0\tinfo\tmain\tfoo.go:42\thello\n",
+		},
+		{
+			desc: "use the supplied EncodeTime, for both the entry and any times added",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     func(t time.Time, enc PrimitiveArrayEncoder) { enc.AppendString(t.String()) },
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+			},
+			extra: func(enc Encoder) {
+				enc.AddTime("extra", _epoch)
+				enc.AddArray("extras", ArrayMarshalerFunc(func(enc ArrayEncoder) error {
+					enc.AppendTime(_epoch)
+					return nil
+				}))
+			},
+			expectedJSON: `{"L":"info","T":"1970-01-01 00:00:00 +0000 UTC","N":"main","C":"foo.go:42","M":"hello","extra":"1970-01-01 00:00:00 +0000 UTC","extras":["1970-01-01 00:00:00 +0000 UTC"],"S":"fake-stack"}` + "\n",
+			expectedConsole: "1970-01-01 00:00:00 +0000 UTC\tinfo\tmain\tfoo.go:42\thello\t" + // plain-text preamble
+				`{"extra": "1970-01-01 00:00:00 +0000 UTC", "extras": ["1970-01-01 00:00:00 +0000 UTC"]}` + // JSON context
+				"\nfake-stack\n", // stacktrace after newline
+		},
+		{
+			desc: "use the supplied EncodeDuration for any durations added",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: StringDurationEncoder,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+			},
+			extra: func(enc Encoder) {
+				enc.AddDuration("extra", time.Second)
+				enc.AddArray("extras", ArrayMarshalerFunc(func(enc ArrayEncoder) error {
+					enc.AppendDuration(time.Minute)
+					return nil
+				}))
+			},
+			expectedJSON: `{"L":"info","T":0,"N":"main","C":"foo.go:42","M":"hello","extra":"1s","extras":["1m0s"],"S":"fake-stack"}` + "\n",
+			expectedConsole: "0\tinfo\tmain\tfoo.go:42\thello\t" + // preamble
+				`{"extra": "1s", "extras": ["1m0s"]}` + // context
+				"\nfake-stack\n", // stacktrace
+		},
+		{
+			desc: "use the supplied EncodeLevel",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    CapitalLevelEncoder,
+				EncodeCaller:   base.EncodeCaller,
+			},
+			expectedJSON:    `{"L":"INFO","T":0,"N":"main","C":"foo.go:42","M":"hello","S":"fake-stack"}` + "\n",
+			expectedConsole: "0\tINFO\tmain\tfoo.go:42\thello\nfake-stack\n",
+		},
+		{
+			desc: "use the supplied EncodeName",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+				EncodeName:     capitalNameEncoder,
+			},
+			expectedJSON:    `{"L":"info","T":0,"N":"MAIN","C":"foo.go:42","M":"hello","S":"fake-stack"}` + "\n",
+			expectedConsole: "0\tinfo\tMAIN\tfoo.go:42\thello\nfake-stack\n",
+		},
+		{
+			desc: "close all open namespaces",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+			},
+			extra: func(enc Encoder) {
+				enc.OpenNamespace("outer")
+				enc.OpenNamespace("inner")
+				enc.AddString("foo", "bar")
+				enc.OpenNamespace("innermost")
+			},
+			expectedJSON: `{"L":"info","T":0,"N":"main","C":"foo.go:42","M":"hello","outer":{"inner":{"foo":"bar","innermost":{}}},"S":"fake-stack"}` + "\n",
+			expectedConsole: "0\tinfo\tmain\tfoo.go:42\thello\t" +
+				`{"outer": {"inner": {"foo": "bar", "innermost": {}}}}` +
+				"\nfake-stack\n",
+		},
+		{
+			desc: "handle no-op EncodeTime",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     func(time.Time, PrimitiveArrayEncoder) {},
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+			},
+			extra:           func(enc Encoder) { enc.AddTime("sometime", time.Unix(0, 100)) },
+			expectedJSON:    `{"L":"info","T":0,"N":"main","C":"foo.go:42","M":"hello","sometime":100,"S":"fake-stack"}` + "\n",
+			expectedConsole: "info\tmain\tfoo.go:42\thello\t" + `{"sometime": 100}` + "\nfake-stack\n",
+		},
+		{
+			desc: "handle no-op EncodeDuration",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: func(time.Duration, PrimitiveArrayEncoder) {},
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+			},
+			extra:           func(enc Encoder) { enc.AddDuration("someduration", time.Microsecond) },
+			expectedJSON:    `{"L":"info","T":0,"N":"main","C":"foo.go:42","M":"hello","someduration":1000,"S":"fake-stack"}` + "\n",
+			expectedConsole: "0\tinfo\tmain\tfoo.go:42\thello\t" + `{"someduration": 1000}` + "\nfake-stack\n",
+		},
+		{
+			desc: "handle no-op EncodeLevel",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    func(Level, PrimitiveArrayEncoder) {},
+				EncodeCaller:   base.EncodeCaller,
+			},
+			expectedJSON:    `{"L":"info","T":0,"N":"main","C":"foo.go:42","M":"hello","S":"fake-stack"}` + "\n",
+			expectedConsole: "0\tmain\tfoo.go:42\thello\nfake-stack\n",
+		},
+		{
+			desc: "handle no-op EncodeCaller",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   func(EntryCaller, PrimitiveArrayEncoder) {},
+			},
+			expectedJSON:    `{"L":"info","T":0,"N":"main","C":"foo.go:42","M":"hello","S":"fake-stack"}` + "\n",
+			expectedConsole: "0\tinfo\tmain\thello\nfake-stack\n",
+		},
+		{
+			desc: "handle no-op EncodeName",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     base.LineEnding,
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+				EncodeName:     func(string, PrimitiveArrayEncoder) {},
+			},
+			expectedJSON:    `{"L":"info","T":0,"N":"main","C":"foo.go:42","M":"hello","S":"fake-stack"}` + "\n",
+			expectedConsole: "0\tinfo\tfoo.go:42\thello\nfake-stack\n",
+		},
+		{
+			desc: "use custom line separator",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				LineEnding:     "\r\n",
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+			},
+			expectedJSON:    `{"L":"info","T":0,"N":"main","C":"foo.go:42","M":"hello","S":"fake-stack"}` + "\r\n",
+			expectedConsole: "0\tinfo\tmain\tfoo.go:42\thello\nfake-stack\r\n",
+		},
+		{
+			desc: "omit line separator definition - fall back to default",
+			cfg: EncoderConfig{
+				LevelKey:       "L",
+				TimeKey:        "T",
+				MessageKey:     "M",
+				NameKey:        "N",
+				CallerKey:      "C",
+				StacktraceKey:  "S",
+				EncodeTime:     base.EncodeTime,
+				EncodeDuration: base.EncodeDuration,
+				EncodeLevel:    base.EncodeLevel,
+				EncodeCaller:   base.EncodeCaller,
+			},
+			expectedJSON:    `{"L":"info","T":0,"N":"main","C":"foo.go:42","M":"hello","S":"fake-stack"}` + DefaultLineEnding,
+			expectedConsole: "0\tinfo\tmain\tfoo.go:42\thello\nfake-stack" + DefaultLineEnding,
+		},
+	}
+
+	for i, tt := range tests {
+		json := NewJSONEncoder(tt.cfg)
+		console := NewConsoleEncoder(tt.cfg)
+		if tt.extra != nil {
+			tt.extra(json)
+			tt.extra(console)
+		}
+		entry := _testEntry
+		if tt.amendEntry != nil {
+			entry = tt.amendEntry(_testEntry)
+		}
+		jsonOut, jsonErr := json.EncodeEntry(entry, nil)
+		if assert.NoError(t, jsonErr, "Unexpected error JSON-encoding entry in case #%d.", i) {
+			assert.Equal(
+				t,
+				tt.expectedJSON,
+				jsonOut.String(),
+				"Unexpected JSON output: expected to %v.", tt.desc,
+			)
+		}
+		consoleOut, consoleErr := console.EncodeEntry(entry, nil)
+		if assert.NoError(t, consoleErr, "Unexpected error console-encoding entry in case #%d.", i) {
+			assert.Equal(
+				t,
+				tt.expectedConsole,
+				consoleOut.String(),
+				"Unexpected console output: expected to %v.", tt.desc,
+			)
+		}
+	}
+}
+
+func TestLevelEncoders(t *testing.T) {
+	tests := []struct {
+		name     string
+		expected interface{} // output of encoding InfoLevel
+	}{
+		{"capital", "INFO"},
+		{"lower", "info"},
+		{"", "info"},
+		{"something-random", "info"},
+	}
+
+	for _, tt := range tests {
+		var le LevelEncoder
+		require.NoError(t, le.UnmarshalText([]byte(tt.name)), "Unexpected error unmarshaling %q.", tt.name)
+		assertAppended(
+			t,
+			tt.expected,
+			func(arr ArrayEncoder) { le(InfoLevel, arr) },
+			"Unexpected output serializing InfoLevel with %q.", tt.name,
+		)
+	}
+}
+
+func TestTimeEncoders(t *testing.T) {
+	moment := time.Unix(100, 50005000).UTC()
+	tests := []struct {
+		name     string
+		expected interface{} // output of serializing moment
+	}{
+		{"iso8601", "1970-01-01T00:01:40.050Z"},
+		{"ISO8601", "1970-01-01T00:01:40.050Z"},
+		{"millis", 100050.005},
+		{"nanos", int64(100050005000)},
+		{"", 100.050005},
+		{"something-random", 100.050005},
+	}
+
+	for _, tt := range tests {
+		var te TimeEncoder
+		require.NoError(t, te.UnmarshalText([]byte(tt.name)), "Unexpected error unmarshaling %q.", tt.name)
+		assertAppended(
+			t,
+			tt.expected,
+			func(arr ArrayEncoder) { te(moment, arr) },
+			"Unexpected output serializing %v with %q.", moment, tt.name,
+		)
+	}
+}
+
+func TestDurationEncoders(t *testing.T) {
+	elapsed := time.Second + 500*time.Nanosecond
+	tests := []struct {
+		name     string
+		expected interface{} // output of serializing elapsed
+	}{
+		{"string", "1.0000005s"},
+		{"nanos", int64(1000000500)},
+		{"", 1.0000005},
+		{"something-random", 1.0000005},
+	}
+
+	for _, tt := range tests {
+		var de DurationEncoder
+		require.NoError(t, de.UnmarshalText([]byte(tt.name)), "Unexpected error unmarshaling %q.", tt.name)
+		assertAppended(
+			t,
+			tt.expected,
+			func(arr ArrayEncoder) { de(elapsed, arr) },
+			"Unexpected output serializing %v with %q.", elapsed, tt.name,
+		)
+	}
+}
+
+func TestCallerEncoders(t *testing.T) {
+	caller := EntryCaller{Defined: true, File: "/home/jack/src/github.com/foo/foo.go", Line: 42}
+	tests := []struct {
+		name     string
+		expected interface{} // output of serializing caller
+	}{
+		{"", "foo/foo.go:42"},
+		{"something-random", "foo/foo.go:42"},
+		{"short", "foo/foo.go:42"},
+		{"full", "/home/jack/src/github.com/foo/foo.go:42"},
+	}
+
+	for _, tt := range tests {
+		var ce CallerEncoder
+		require.NoError(t, ce.UnmarshalText([]byte(tt.name)), "Unexpected error unmarshaling %q.", tt.name)
+		assertAppended(
+			t,
+			tt.expected,
+			func(arr ArrayEncoder) { ce(caller, arr) },
+			"Unexpected output serializing file name as %v with %q.", tt.expected, tt.name,
+		)
+	}
+}
+
+func TestNameEncoders(t *testing.T) {
+	tests := []struct {
+		name     string
+		expected interface{} // output of encoding InfoLevel
+	}{
+		{"", "main"},
+		{"full", "main"},
+		{"something-random", "main"},
+	}
+
+	for _, tt := range tests {
+		var ne NameEncoder
+		require.NoError(t, ne.UnmarshalText([]byte(tt.name)), "Unexpected error unmarshaling %q.", tt.name)
+		assertAppended(
+			t,
+			tt.expected,
+			func(arr ArrayEncoder) { ne("main", arr) },
+			"Unexpected output serializing logger name with %q.", tt.name,
+		)
+	}
+}
+
+func assertAppended(t testing.TB, expected interface{}, f func(ArrayEncoder), msgAndArgs ...interface{}) {
+	mem := NewMapObjectEncoder()
+	mem.AddArray("k", ArrayMarshalerFunc(func(arr ArrayEncoder) error {
+		f(arr)
+		return nil
+	}))
+	arr := mem.Fields["k"].([]interface{})
+	require.Equal(t, 1, len(arr), "Expected to append exactly one element to array.")
+	assert.Equal(t, expected, arr[0], msgAndArgs...)
+}
diff --git a/vendor/go.uber.org/zap/zapcore/entry.go b/vendor/go.uber.org/zap/zapcore/entry.go
new file mode 100644
index 0000000..7d9893f
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/entry.go
@@ -0,0 +1,257 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"fmt"
+	"strings"
+	"sync"
+	"time"
+
+	"go.uber.org/zap/internal/bufferpool"
+	"go.uber.org/zap/internal/exit"
+
+	"go.uber.org/multierr"
+)
+
+var (
+	_cePool = sync.Pool{New: func() interface{} {
+		// Pre-allocate some space for cores.
+		return &CheckedEntry{
+			cores: make([]Core, 4),
+		}
+	}}
+)
+
+func getCheckedEntry() *CheckedEntry {
+	ce := _cePool.Get().(*CheckedEntry)
+	ce.reset()
+	return ce
+}
+
+func putCheckedEntry(ce *CheckedEntry) {
+	if ce == nil {
+		return
+	}
+	_cePool.Put(ce)
+}
+
+// NewEntryCaller makes an EntryCaller from the return signature of
+// runtime.Caller.
+func NewEntryCaller(pc uintptr, file string, line int, ok bool) EntryCaller {
+	if !ok {
+		return EntryCaller{}
+	}
+	return EntryCaller{
+		PC:      pc,
+		File:    file,
+		Line:    line,
+		Defined: true,
+	}
+}
+
+// EntryCaller represents the caller of a logging function.
+type EntryCaller struct {
+	Defined bool
+	PC      uintptr
+	File    string
+	Line    int
+}
+
+// String returns the full path and line number of the caller.
+func (ec EntryCaller) String() string {
+	return ec.FullPath()
+}
+
+// FullPath returns a /full/path/to/package/file:line description of the
+// caller.
+func (ec EntryCaller) FullPath() string {
+	if !ec.Defined {
+		return "undefined"
+	}
+	buf := bufferpool.Get()
+	buf.AppendString(ec.File)
+	buf.AppendByte(':')
+	buf.AppendInt(int64(ec.Line))
+	caller := buf.String()
+	buf.Free()
+	return caller
+}
+
+// TrimmedPath returns a package/file:line description of the caller,
+// preserving only the leaf directory name and file name.
+func (ec EntryCaller) TrimmedPath() string {
+	if !ec.Defined {
+		return "undefined"
+	}
+	// nb. To make sure we trim the path correctly on Windows too, we
+	// counter-intuitively need to use '/' and *not* os.PathSeparator here,
+	// because the path given originates from Go stdlib, specifically
+	// runtime.Caller() which (as of Mar/17) returns forward slashes even on
+	// Windows.
+	//
+	// See https://github.com/golang/go/issues/3335
+	// and https://github.com/golang/go/issues/18151
+	//
+	// for discussion on the issue on Go side.
+	//
+	// Find the last separator.
+	//
+	idx := strings.LastIndexByte(ec.File, '/')
+	if idx == -1 {
+		return ec.FullPath()
+	}
+	// Find the penultimate separator.
+	idx = strings.LastIndexByte(ec.File[:idx], '/')
+	if idx == -1 {
+		return ec.FullPath()
+	}
+	buf := bufferpool.Get()
+	// Keep everything after the penultimate separator.
+	buf.AppendString(ec.File[idx+1:])
+	buf.AppendByte(':')
+	buf.AppendInt(int64(ec.Line))
+	caller := buf.String()
+	buf.Free()
+	return caller
+}
+
+// An Entry represents a complete log message. The entry's structured context
+// is already serialized, but the log level, time, message, and call site
+// information are available for inspection and modification.
+//
+// Entries are pooled, so any functions that accept them MUST be careful not to
+// retain references to them.
+type Entry struct {
+	Level      Level
+	Time       time.Time
+	LoggerName string
+	Message    string
+	Caller     EntryCaller
+	Stack      string
+}
+
+// CheckWriteAction indicates what action to take after a log entry is
+// processed. Actions are ordered in increasing severity.
+type CheckWriteAction uint8
+
+const (
+	// WriteThenNoop indicates that nothing special needs to be done. It's the
+	// default behavior.
+	WriteThenNoop CheckWriteAction = iota
+	// WriteThenPanic causes a panic after Write.
+	WriteThenPanic
+	// WriteThenFatal causes a fatal os.Exit after Write.
+	WriteThenFatal
+)
+
+// CheckedEntry is an Entry together with a collection of Cores that have
+// already agreed to log it.
+//
+// CheckedEntry references should be created by calling AddCore or Should on a
+// nil *CheckedEntry. References are returned to a pool after Write, and MUST
+// NOT be retained after calling their Write method.
+type CheckedEntry struct {
+	Entry
+	ErrorOutput WriteSyncer
+	dirty       bool // best-effort detection of pool misuse
+	should      CheckWriteAction
+	cores       []Core
+}
+
+func (ce *CheckedEntry) reset() {
+	ce.Entry = Entry{}
+	ce.ErrorOutput = nil
+	ce.dirty = false
+	ce.should = WriteThenNoop
+	for i := range ce.cores {
+		// don't keep references to cores
+		ce.cores[i] = nil
+	}
+	ce.cores = ce.cores[:0]
+}
+
+// Write writes the entry to the stored Cores, returns any errors, and returns
+// the CheckedEntry reference to a pool for immediate re-use. Finally, it
+// executes any required CheckWriteAction.
+func (ce *CheckedEntry) Write(fields ...Field) {
+	if ce == nil {
+		return
+	}
+
+	if ce.dirty {
+		if ce.ErrorOutput != nil {
+			// Make a best effort to detect unsafe re-use of this CheckedEntry.
+			// If the entry is dirty, log an internal error; because the
+			// CheckedEntry is being used after it was returned to the pool,
+			// the message may be an amalgamation from multiple call sites.
+			fmt.Fprintf(ce.ErrorOutput, "%v Unsafe CheckedEntry re-use near Entry %+v.\n", time.Now(), ce.Entry)
+			ce.ErrorOutput.Sync()
+		}
+		return
+	}
+	ce.dirty = true
+
+	var err error
+	for i := range ce.cores {
+		err = multierr.Append(err, ce.cores[i].Write(ce.Entry, fields))
+	}
+	if ce.ErrorOutput != nil {
+		if err != nil {
+			fmt.Fprintf(ce.ErrorOutput, "%v write error: %v\n", time.Now(), err)
+			ce.ErrorOutput.Sync()
+		}
+	}
+
+	should, msg := ce.should, ce.Message
+	putCheckedEntry(ce)
+
+	switch should {
+	case WriteThenPanic:
+		panic(msg)
+	case WriteThenFatal:
+		exit.Exit()
+	}
+}
+
+// AddCore adds a Core that has agreed to log this CheckedEntry. It's intended to be
+// used by Core.Check implementations, and is safe to call on nil CheckedEntry
+// references.
+func (ce *CheckedEntry) AddCore(ent Entry, core Core) *CheckedEntry {
+	if ce == nil {
+		ce = getCheckedEntry()
+		ce.Entry = ent
+	}
+	ce.cores = append(ce.cores, core)
+	return ce
+}
+
+// Should sets this CheckedEntry's CheckWriteAction, which controls whether a
+// Core will panic or fatal after writing this log entry. Like AddCore, it's
+// safe to call on nil CheckedEntry references.
+func (ce *CheckedEntry) Should(ent Entry, should CheckWriteAction) *CheckedEntry {
+	if ce == nil {
+		ce = getCheckedEntry()
+		ce.Entry = ent
+	}
+	ce.should = should
+	return ce
+}
diff --git a/vendor/go.uber.org/zap/zapcore/entry_test.go b/vendor/go.uber.org/zap/zapcore/entry_test.go
new file mode 100644
index 0000000..569c4e1
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/entry_test.go
@@ -0,0 +1,107 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"sync"
+	"testing"
+
+	"go.uber.org/zap/internal/exit"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPutNilEntry(t *testing.T) {
+	// Pooling nil entries defeats the purpose.
+	var wg sync.WaitGroup
+	wg.Add(2)
+
+	go func() {
+		defer wg.Done()
+		for i := 0; i < 1000; i++ {
+			putCheckedEntry(nil)
+		}
+	}()
+
+	go func() {
+		defer wg.Done()
+		for i := 0; i < 1000; i++ {
+			ce := getCheckedEntry()
+			assert.NotNil(t, ce, "Expected only non-nil CheckedEntries in pool.")
+			assert.False(t, ce.dirty, "Unexpected dirty bit set.")
+			assert.Nil(t, ce.ErrorOutput, "Non-nil ErrorOutput.")
+			assert.Equal(t, WriteThenNoop, ce.should, "Unexpected terminal behavior.")
+			assert.Equal(t, 0, len(ce.cores), "Expected empty slice of cores.")
+			assert.True(t, cap(ce.cores) > 0, "Expected pooled CheckedEntries to pre-allocate slice of Cores.")
+		}
+	}()
+
+	wg.Wait()
+}
+
+func TestEntryCaller(t *testing.T) {
+	tests := []struct {
+		caller EntryCaller
+		full   string
+		short  string
+	}{
+		{
+			caller: NewEntryCaller(100, "/path/to/foo.go", 42, false),
+			full:   "undefined",
+			short:  "undefined",
+		},
+		{
+			caller: NewEntryCaller(100, "/path/to/foo.go", 42, true),
+			full:   "/path/to/foo.go:42",
+			short:  "to/foo.go:42",
+		},
+		{
+			caller: NewEntryCaller(100, "to/foo.go", 42, true),
+			full:   "to/foo.go:42",
+			short:  "to/foo.go:42",
+		},
+	}
+
+	for _, tt := range tests {
+		assert.Equal(t, tt.full, tt.caller.String(), "Unexpected string from EntryCaller.")
+		assert.Equal(t, tt.full, tt.caller.FullPath(), "Unexpected FullPath from EntryCaller.")
+		assert.Equal(t, tt.short, tt.caller.TrimmedPath(), "Unexpected TrimmedPath from EntryCaller.")
+	}
+}
+
+func TestCheckedEntryWrite(t *testing.T) {
+	// Nil checked entries are safe.
+	var ce *CheckedEntry
+	assert.NotPanics(t, func() { ce.Write() }, "Unexpected panic writing nil CheckedEntry.")
+
+	// WriteThenPanic
+	ce = ce.Should(Entry{}, WriteThenPanic)
+	assert.Panics(t, func() { ce.Write() }, "Expected to panic when WriteThenPanic is set.")
+	ce.reset()
+
+	// WriteThenFatal
+	ce = ce.Should(Entry{}, WriteThenFatal)
+	stub := exit.WithStub(func() {
+		ce.Write()
+	})
+	assert.True(t, stub.Exited, "Expected to exit when WriteThenFatal is set.")
+	ce.reset()
+}
diff --git a/vendor/go.uber.org/zap/zapcore/error.go b/vendor/go.uber.org/zap/zapcore/error.go
new file mode 100644
index 0000000..a67c7ba
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/error.go
@@ -0,0 +1,120 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"fmt"
+	"sync"
+)
+
+// Encodes the given error into fields of an object. A field with the given
+// name is added for the error message.
+//
+// If the error implements fmt.Formatter, a field with the name ${key}Verbose
+// is also added with the full verbose error message.
+//
+// Finally, if the error implements errorGroup (from go.uber.org/multierr) or
+// causer (from github.com/pkg/errors), a ${key}Causes field is added with an
+// array of objects containing the errors this error was comprised of.
+//
+//  {
+//    "error": err.Error(),
+//    "errorVerbose": fmt.Sprintf("%+v", err),
+//    "errorCauses": [
+//      ...
+//    ],
+//  }
+func encodeError(key string, err error, enc ObjectEncoder) error {
+	basic := err.Error()
+	enc.AddString(key, basic)
+
+	switch e := err.(type) {
+	case errorGroup:
+		return enc.AddArray(key+"Causes", errArray(e.Errors()))
+	case fmt.Formatter:
+		verbose := fmt.Sprintf("%+v", e)
+		if verbose != basic {
+			// This is a rich error type, like those produced by
+			// github.com/pkg/errors.
+			enc.AddString(key+"Verbose", verbose)
+		}
+	}
+	return nil
+}
+
+type errorGroup interface {
+	// Provides read-only access to the underlying list of errors, preferably
+	// without causing any allocs.
+	Errors() []error
+}
+
+type causer interface {
+	// Provides access to the error that caused this error.
+	Cause() error
+}
+
+// Note that errArry and errArrayElem are very similar to the version
+// implemented in the top-level error.go file. We can't re-use this because
+// that would require exporting errArray as part of the zapcore API.
+
+// Encodes a list of errors using the standard error encoding logic.
+type errArray []error
+
+func (errs errArray) MarshalLogArray(arr ArrayEncoder) error {
+	for i := range errs {
+		if errs[i] == nil {
+			continue
+		}
+
+		el := newErrArrayElem(errs[i])
+		arr.AppendObject(el)
+		el.Free()
+	}
+	return nil
+}
+
+var _errArrayElemPool = sync.Pool{New: func() interface{} {
+	return &errArrayElem{}
+}}
+
+// Encodes any error into a {"error": ...} re-using the same errors logic.
+//
+// May be passed in place of an array to build a single-element array.
+type errArrayElem struct{ err error }
+
+func newErrArrayElem(err error) *errArrayElem {
+	e := _errArrayElemPool.Get().(*errArrayElem)
+	e.err = err
+	return e
+}
+
+func (e *errArrayElem) MarshalLogArray(arr ArrayEncoder) error {
+	return arr.AppendObject(e)
+}
+
+func (e *errArrayElem) MarshalLogObject(enc ObjectEncoder) error {
+	return encodeError("error", e.err, enc)
+}
+
+func (e *errArrayElem) Free() {
+	e.err = nil
+	_errArrayElemPool.Put(e)
+}
diff --git a/vendor/go.uber.org/zap/zapcore/error_test.go b/vendor/go.uber.org/zap/zapcore/error_test.go
new file mode 100644
index 0000000..900f520
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/error_test.go
@@ -0,0 +1,177 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore_test
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"testing"
+
+	richErrors "github.com/pkg/errors"
+	"github.com/stretchr/testify/assert"
+
+	"go.uber.org/multierr"
+	. "go.uber.org/zap/zapcore"
+)
+
+type errTooManyUsers int
+
+func (e errTooManyUsers) Error() string {
+	return fmt.Sprintf("%d too many users", int(e))
+}
+
+func (e errTooManyUsers) Format(s fmt.State, verb rune) {
+	// Implement fmt.Formatter, but don't add any information beyond the basic
+	// Error method.
+	if verb == 'v' && s.Flag('+') {
+		io.WriteString(s, e.Error())
+	}
+}
+
+type customMultierr struct{}
+
+func (e customMultierr) Error() string {
+	return "great sadness"
+}
+
+func (e customMultierr) Errors() []error {
+	return []error{
+		errors.New("foo"),
+		nil,
+		multierr.Append(
+			errors.New("bar"),
+			errors.New("baz"),
+		),
+	}
+}
+
+func TestErrorEncoding(t *testing.T) {
+	tests := []struct {
+		k     string
+		t     FieldType // defaults to ErrorType
+		iface interface{}
+		want  map[string]interface{}
+	}{
+		{
+			k:     "k",
+			iface: errTooManyUsers(2),
+			want: map[string]interface{}{
+				"k": "2 too many users",
+			},
+		},
+		{
+			k: "err",
+			iface: multierr.Combine(
+				errors.New("foo"),
+				errors.New("bar"),
+				errors.New("baz"),
+			),
+			want: map[string]interface{}{
+				"err": "foo; bar; baz",
+				"errCauses": []interface{}{
+					map[string]interface{}{"error": "foo"},
+					map[string]interface{}{"error": "bar"},
+					map[string]interface{}{"error": "baz"},
+				},
+			},
+		},
+		{
+			k:     "e",
+			iface: customMultierr{},
+			want: map[string]interface{}{
+				"e": "great sadness",
+				"eCauses": []interface{}{
+					map[string]interface{}{"error": "foo"},
+					map[string]interface{}{
+						"error": "bar; baz",
+						"errorCauses": []interface{}{
+							map[string]interface{}{"error": "bar"},
+							map[string]interface{}{"error": "baz"},
+						},
+					},
+				},
+			},
+		},
+		{
+			k:     "k",
+			iface: richErrors.WithMessage(errors.New("egad"), "failed"),
+			want: map[string]interface{}{
+				"k":        "failed: egad",
+				"kVerbose": "egad\nfailed",
+			},
+		},
+		{
+			k: "error",
+			iface: multierr.Combine(
+				richErrors.WithMessage(
+					multierr.Combine(errors.New("foo"), errors.New("bar")),
+					"hello",
+				),
+				errors.New("baz"),
+				richErrors.WithMessage(errors.New("qux"), "world"),
+			),
+			want: map[string]interface{}{
+				"error": "hello: foo; bar; baz; world: qux",
+				"errorCauses": []interface{}{
+					map[string]interface{}{
+						"error": "hello: foo; bar",
+						"errorVerbose": "the following errors occurred:\n" +
+							" -  foo\n" +
+							" -  bar\n" +
+							"hello",
+					},
+					map[string]interface{}{"error": "baz"},
+					map[string]interface{}{"error": "world: qux", "errorVerbose": "qux\nworld"},
+				},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		if tt.t == UnknownType {
+			tt.t = ErrorType
+		}
+
+		enc := NewMapObjectEncoder()
+		f := Field{Key: tt.k, Type: tt.t, Interface: tt.iface}
+		f.AddTo(enc)
+		assert.Equal(t, tt.want, enc.Fields, "Unexpected output from field %+v.", f)
+	}
+}
+
+func TestRichErrorSupport(t *testing.T) {
+	f := Field{
+		Type:      ErrorType,
+		Interface: richErrors.WithMessage(richErrors.New("egad"), "failed"),
+		Key:       "k",
+	}
+	enc := NewMapObjectEncoder()
+	f.AddTo(enc)
+	assert.Equal(t, "failed: egad", enc.Fields["k"], "Unexpected basic error message.")
+
+	serialized := enc.Fields["kVerbose"]
+	// Don't assert the exact format used by a third-party package, but ensure
+	// that some critical elements are present.
+	assert.Regexp(t, `egad`, serialized, "Expected original error message to be present.")
+	assert.Regexp(t, `failed`, serialized, "Expected error annotation to be present.")
+	assert.Regexp(t, `TestRichErrorSupport`, serialized, "Expected calling function to be present in stacktrace.")
+}
diff --git a/vendor/go.uber.org/zap/zapcore/field.go b/vendor/go.uber.org/zap/zapcore/field.go
new file mode 100644
index 0000000..6a5e33e
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/field.go
@@ -0,0 +1,201 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"bytes"
+	"fmt"
+	"math"
+	"reflect"
+	"time"
+)
+
+// A FieldType indicates which member of the Field union struct should be used
+// and how it should be serialized.
+type FieldType uint8
+
+const (
+	// UnknownType is the default field type. Attempting to add it to an encoder will panic.
+	UnknownType FieldType = iota
+	// ArrayMarshalerType indicates that the field carries an ArrayMarshaler.
+	ArrayMarshalerType
+	// ObjectMarshalerType indicates that the field carries an ObjectMarshaler.
+	ObjectMarshalerType
+	// BinaryType indicates that the field carries an opaque binary blob.
+	BinaryType
+	// BoolType indicates that the field carries a bool.
+	BoolType
+	// ByteStringType indicates that the field carries UTF-8 encoded bytes.
+	ByteStringType
+	// Complex128Type indicates that the field carries a complex128.
+	Complex128Type
+	// Complex64Type indicates that the field carries a complex128.
+	Complex64Type
+	// DurationType indicates that the field carries a time.Duration.
+	DurationType
+	// Float64Type indicates that the field carries a float64.
+	Float64Type
+	// Float32Type indicates that the field carries a float32.
+	Float32Type
+	// Int64Type indicates that the field carries an int64.
+	Int64Type
+	// Int32Type indicates that the field carries an int32.
+	Int32Type
+	// Int16Type indicates that the field carries an int16.
+	Int16Type
+	// Int8Type indicates that the field carries an int8.
+	Int8Type
+	// StringType indicates that the field carries a string.
+	StringType
+	// TimeType indicates that the field carries a time.Time.
+	TimeType
+	// Uint64Type indicates that the field carries a uint64.
+	Uint64Type
+	// Uint32Type indicates that the field carries a uint32.
+	Uint32Type
+	// Uint16Type indicates that the field carries a uint16.
+	Uint16Type
+	// Uint8Type indicates that the field carries a uint8.
+	Uint8Type
+	// UintptrType indicates that the field carries a uintptr.
+	UintptrType
+	// ReflectType indicates that the field carries an interface{}, which should
+	// be serialized using reflection.
+	ReflectType
+	// NamespaceType signals the beginning of an isolated namespace. All
+	// subsequent fields should be added to the new namespace.
+	NamespaceType
+	// StringerType indicates that the field carries a fmt.Stringer.
+	StringerType
+	// ErrorType indicates that the field carries an error.
+	ErrorType
+	// SkipType indicates that the field is a no-op.
+	SkipType
+)
+
+// A Field is a marshaling operation used to add a key-value pair to a logger's
+// context. Most fields are lazily marshaled, so it's inexpensive to add fields
+// to disabled debug-level log statements.
+type Field struct {
+	Key       string
+	Type      FieldType
+	Integer   int64
+	String    string
+	Interface interface{}
+}
+
+// AddTo exports a field through the ObjectEncoder interface. It's primarily
+// useful to library authors, and shouldn't be necessary in most applications.
+func (f Field) AddTo(enc ObjectEncoder) {
+	var err error
+
+	switch f.Type {
+	case ArrayMarshalerType:
+		err = enc.AddArray(f.Key, f.Interface.(ArrayMarshaler))
+	case ObjectMarshalerType:
+		err = enc.AddObject(f.Key, f.Interface.(ObjectMarshaler))
+	case BinaryType:
+		enc.AddBinary(f.Key, f.Interface.([]byte))
+	case BoolType:
+		enc.AddBool(f.Key, f.Integer == 1)
+	case ByteStringType:
+		enc.AddByteString(f.Key, f.Interface.([]byte))
+	case Complex128Type:
+		enc.AddComplex128(f.Key, f.Interface.(complex128))
+	case Complex64Type:
+		enc.AddComplex64(f.Key, f.Interface.(complex64))
+	case DurationType:
+		enc.AddDuration(f.Key, time.Duration(f.Integer))
+	case Float64Type:
+		enc.AddFloat64(f.Key, math.Float64frombits(uint64(f.Integer)))
+	case Float32Type:
+		enc.AddFloat32(f.Key, math.Float32frombits(uint32(f.Integer)))
+	case Int64Type:
+		enc.AddInt64(f.Key, f.Integer)
+	case Int32Type:
+		enc.AddInt32(f.Key, int32(f.Integer))
+	case Int16Type:
+		enc.AddInt16(f.Key, int16(f.Integer))
+	case Int8Type:
+		enc.AddInt8(f.Key, int8(f.Integer))
+	case StringType:
+		enc.AddString(f.Key, f.String)
+	case TimeType:
+		if f.Interface != nil {
+			enc.AddTime(f.Key, time.Unix(0, f.Integer).In(f.Interface.(*time.Location)))
+		} else {
+			// Fall back to UTC if location is nil.
+			enc.AddTime(f.Key, time.Unix(0, f.Integer))
+		}
+	case Uint64Type:
+		enc.AddUint64(f.Key, uint64(f.Integer))
+	case Uint32Type:
+		enc.AddUint32(f.Key, uint32(f.Integer))
+	case Uint16Type:
+		enc.AddUint16(f.Key, uint16(f.Integer))
+	case Uint8Type:
+		enc.AddUint8(f.Key, uint8(f.Integer))
+	case UintptrType:
+		enc.AddUintptr(f.Key, uintptr(f.Integer))
+	case ReflectType:
+		err = enc.AddReflected(f.Key, f.Interface)
+	case NamespaceType:
+		enc.OpenNamespace(f.Key)
+	case StringerType:
+		enc.AddString(f.Key, f.Interface.(fmt.Stringer).String())
+	case ErrorType:
+		encodeError(f.Key, f.Interface.(error), enc)
+	case SkipType:
+		break
+	default:
+		panic(fmt.Sprintf("unknown field type: %v", f))
+	}
+
+	if err != nil {
+		enc.AddString(fmt.Sprintf("%sError", f.Key), err.Error())
+	}
+}
+
+// Equals returns whether two fields are equal. For non-primitive types such as
+// errors, marshalers, or reflect types, it uses reflect.DeepEqual.
+func (f Field) Equals(other Field) bool {
+	if f.Type != other.Type {
+		return false
+	}
+	if f.Key != other.Key {
+		return false
+	}
+
+	switch f.Type {
+	case BinaryType, ByteStringType:
+		return bytes.Equal(f.Interface.([]byte), other.Interface.([]byte))
+	case ArrayMarshalerType, ObjectMarshalerType, ErrorType, ReflectType:
+		return reflect.DeepEqual(f.Interface, other.Interface)
+	default:
+		return f == other
+	}
+}
+
+func addFields(enc ObjectEncoder, fields []Field) {
+	for i := range fields {
+		fields[i].AddTo(enc)
+	}
+}
diff --git a/vendor/go.uber.org/zap/zapcore/field_test.go b/vendor/go.uber.org/zap/zapcore/field_test.go
new file mode 100644
index 0000000..fb722b4
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/field_test.go
@@ -0,0 +1,231 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore_test
+
+import (
+	"errors"
+	"fmt"
+	"math"
+	"testing"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/stretchr/testify/assert"
+
+	. "go.uber.org/zap/zapcore"
+)
+
+type users int
+
+func (u users) String() string {
+	return fmt.Sprintf("%d users", int(u))
+}
+
+func (u users) MarshalLogObject(enc ObjectEncoder) error {
+	if int(u) < 0 {
+		return errors.New("too few users")
+	}
+	enc.AddInt("users", int(u))
+	return nil
+}
+
+func (u users) MarshalLogArray(enc ArrayEncoder) error {
+	if int(u) < 0 {
+		return errors.New("too few users")
+	}
+	for i := 0; i < int(u); i++ {
+		enc.AppendString("user")
+	}
+	return nil
+}
+
+func TestUnknownFieldType(t *testing.T) {
+	unknown := Field{Key: "k", String: "foo"}
+	assert.Equal(t, UnknownType, unknown.Type, "Expected zero value of FieldType to be UnknownType.")
+	assert.Panics(t, func() {
+		unknown.AddTo(NewMapObjectEncoder())
+	}, "Expected using a field with unknown type to panic.")
+}
+
+func TestFieldAddingError(t *testing.T) {
+	tests := []struct {
+		t    FieldType
+		want interface{}
+	}{
+		{ArrayMarshalerType, []interface{}(nil)},
+		{ObjectMarshalerType, map[string]interface{}{}},
+	}
+	for _, tt := range tests {
+		f := Field{Key: "k", Interface: users(-1), Type: tt.t}
+		enc := NewMapObjectEncoder()
+		assert.NotPanics(t, func() { f.AddTo(enc) }, "Unexpected panic when adding fields returns an error.")
+		assert.Equal(t, tt.want, enc.Fields["k"], "On error, expected zero value in field.Key.")
+		assert.Equal(t, "too few users", enc.Fields["kError"], "Expected error message in log context.")
+	}
+}
+
+func TestFields(t *testing.T) {
+	tests := []struct {
+		t     FieldType
+		i     int64
+		s     string
+		iface interface{}
+		want  interface{}
+	}{
+		{t: ArrayMarshalerType, iface: users(2), want: []interface{}{"user", "user"}},
+		{t: ObjectMarshalerType, iface: users(2), want: map[string]interface{}{"users": 2}},
+		{t: BinaryType, iface: []byte("foo"), want: []byte("foo")},
+		{t: BoolType, i: 0, want: false},
+		{t: ByteStringType, iface: []byte("foo"), want: "foo"},
+		{t: Complex128Type, iface: 1 + 2i, want: 1 + 2i},
+		{t: Complex64Type, iface: complex64(1 + 2i), want: complex64(1 + 2i)},
+		{t: DurationType, i: 1000, want: time.Microsecond},
+		{t: Float64Type, i: int64(math.Float64bits(3.14)), want: 3.14},
+		{t: Float32Type, i: int64(math.Float32bits(3.14)), want: float32(3.14)},
+		{t: Int64Type, i: 42, want: int64(42)},
+		{t: Int32Type, i: 42, want: int32(42)},
+		{t: Int16Type, i: 42, want: int16(42)},
+		{t: Int8Type, i: 42, want: int8(42)},
+		{t: StringType, s: "foo", want: "foo"},
+		{t: TimeType, i: 1000, iface: time.UTC, want: time.Unix(0, 1000).In(time.UTC)},
+		{t: TimeType, i: 1000, want: time.Unix(0, 1000)},
+		{t: Uint64Type, i: 42, want: uint64(42)},
+		{t: Uint32Type, i: 42, want: uint32(42)},
+		{t: Uint16Type, i: 42, want: uint16(42)},
+		{t: Uint8Type, i: 42, want: uint8(42)},
+		{t: UintptrType, i: 42, want: uintptr(42)},
+		{t: ReflectType, iface: users(2), want: users(2)},
+		{t: NamespaceType, want: map[string]interface{}{}},
+		{t: StringerType, iface: users(2), want: "2 users"},
+		{t: SkipType, want: interface{}(nil)},
+	}
+
+	for _, tt := range tests {
+		enc := NewMapObjectEncoder()
+		f := Field{Key: "k", Type: tt.t, Integer: tt.i, Interface: tt.iface, String: tt.s}
+		f.AddTo(enc)
+		assert.Equal(t, tt.want, enc.Fields["k"], "Unexpected output from field %+v.", f)
+
+		delete(enc.Fields, "k")
+		assert.Equal(t, 0, len(enc.Fields), "Unexpected extra fields present.")
+
+		assert.True(t, f.Equals(f), "Field does not equal itself")
+	}
+}
+
+func TestEquals(t *testing.T) {
+	tests := []struct {
+		a, b Field
+		want bool
+	}{
+		{
+			a:    zap.Int16("a", 1),
+			b:    zap.Int32("a", 1),
+			want: false,
+		},
+		{
+			a:    zap.String("k", "a"),
+			b:    zap.String("k", "a"),
+			want: true,
+		},
+		{
+			a:    zap.String("k", "a"),
+			b:    zap.String("k2", "a"),
+			want: false,
+		},
+		{
+			a:    zap.String("k", "a"),
+			b:    zap.String("k", "b"),
+			want: false,
+		},
+		{
+			a:    zap.Time("k", time.Unix(1000, 1000)),
+			b:    zap.Time("k", time.Unix(1000, 1000)),
+			want: true,
+		},
+		{
+			a:    zap.Time("k", time.Unix(1000, 1000).In(time.UTC)),
+			b:    zap.Time("k", time.Unix(1000, 1000).In(time.FixedZone("TEST", -8))),
+			want: false,
+		},
+		{
+			a:    zap.Time("k", time.Unix(1000, 1000)),
+			b:    zap.Time("k", time.Unix(1000, 2000)),
+			want: false,
+		},
+		{
+			a:    zap.Binary("k", []byte{1, 2}),
+			b:    zap.Binary("k", []byte{1, 2}),
+			want: true,
+		},
+		{
+			a:    zap.Binary("k", []byte{1, 2}),
+			b:    zap.Binary("k", []byte{1, 3}),
+			want: false,
+		},
+		{
+			a:    zap.ByteString("k", []byte("abc")),
+			b:    zap.ByteString("k", []byte("abc")),
+			want: true,
+		},
+		{
+			a:    zap.ByteString("k", []byte("abc")),
+			b:    zap.ByteString("k", []byte("abd")),
+			want: false,
+		},
+		{
+			a:    zap.Ints("k", []int{1, 2}),
+			b:    zap.Ints("k", []int{1, 2}),
+			want: true,
+		},
+		{
+			a:    zap.Ints("k", []int{1, 2}),
+			b:    zap.Ints("k", []int{1, 3}),
+			want: false,
+		},
+		{
+			a:    zap.Object("k", users(10)),
+			b:    zap.Object("k", users(10)),
+			want: true,
+		},
+		{
+			a:    zap.Object("k", users(10)),
+			b:    zap.Object("k", users(20)),
+			want: false,
+		},
+		{
+			a:    zap.Any("k", map[string]string{"a": "b"}),
+			b:    zap.Any("k", map[string]string{"a": "b"}),
+			want: true,
+		},
+		{
+			a:    zap.Any("k", map[string]string{"a": "b"}),
+			b:    zap.Any("k", map[string]string{"a": "d"}),
+			want: false,
+		},
+	}
+
+	for _, tt := range tests {
+		assert.Equal(t, tt.want, tt.a.Equals(tt.b), "a.Equals(b) a: %#v b: %#v", tt.a, tt.b)
+		assert.Equal(t, tt.want, tt.b.Equals(tt.a), "b.Equals(a) a: %#v b: %#v", tt.a, tt.b)
+	}
+}
diff --git a/vendor/go.uber.org/zap/zapcore/hook.go b/vendor/go.uber.org/zap/zapcore/hook.go
new file mode 100644
index 0000000..5db4afb
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/hook.go
@@ -0,0 +1,68 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import "go.uber.org/multierr"
+
+type hooked struct {
+	Core
+	funcs []func(Entry) error
+}
+
+// RegisterHooks wraps a Core and runs a collection of user-defined callback
+// hooks each time a message is logged. Execution of the callbacks is blocking.
+//
+// This offers users an easy way to register simple callbacks (e.g., metrics
+// collection) without implementing the full Core interface.
+func RegisterHooks(core Core, hooks ...func(Entry) error) Core {
+	funcs := append([]func(Entry) error{}, hooks...)
+	return &hooked{
+		Core:  core,
+		funcs: funcs,
+	}
+}
+
+func (h *hooked) Check(ent Entry, ce *CheckedEntry) *CheckedEntry {
+	// Let the wrapped Core decide whether to log this message or not. This
+	// also gives the downstream a chance to register itself directly with the
+	// CheckedEntry.
+	if downstream := h.Core.Check(ent, ce); downstream != nil {
+		return downstream.AddCore(ent, h)
+	}
+	return ce
+}
+
+func (h *hooked) With(fields []Field) Core {
+	return &hooked{
+		Core:  h.Core.With(fields),
+		funcs: h.funcs,
+	}
+}
+
+func (h *hooked) Write(ent Entry, _ []Field) error {
+	// Since our downstream had a chance to register itself directly with the
+	// CheckedMessage, we don't need to call it here.
+	var err error
+	for i := range h.funcs {
+		err = multierr.Append(err, h.funcs[i](ent))
+	}
+	return err
+}
diff --git a/vendor/go.uber.org/zap/zapcore/hook_test.go b/vendor/go.uber.org/zap/zapcore/hook_test.go
new file mode 100644
index 0000000..0764888
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/hook_test.go
@@ -0,0 +1,73 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore_test
+
+import (
+	"testing"
+
+	. "go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest/observer"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestHooks(t *testing.T) {
+	tests := []struct {
+		entryLevel Level
+		coreLevel  Level
+		expectCall bool
+	}{
+		{DebugLevel, InfoLevel, false},
+		{InfoLevel, InfoLevel, true},
+		{WarnLevel, InfoLevel, true},
+	}
+
+	for _, tt := range tests {
+		fac, logs := observer.New(tt.coreLevel)
+		intField := makeInt64Field("foo", 42)
+		ent := Entry{Message: "bar", Level: tt.entryLevel}
+
+		var called int
+		f := func(e Entry) error {
+			called++
+			assert.Equal(t, ent, e, "Hook called with unexpected Entry.")
+			return nil
+		}
+
+		h := RegisterHooks(fac, f)
+		if ce := h.With([]Field{intField}).Check(ent, nil); ce != nil {
+			ce.Write()
+		}
+
+		if tt.expectCall {
+			assert.Equal(t, 1, called, "Expected to call hook once.")
+			assert.Equal(
+				t,
+				[]observer.LoggedEntry{{Entry: ent, Context: []Field{intField}}},
+				logs.AllUntimed(),
+				"Unexpected logs written out.",
+			)
+		} else {
+			assert.Equal(t, 0, called, "Didn't expect to call hook.")
+			assert.Equal(t, 0, logs.Len(), "Unexpected logs written out.")
+		}
+	}
+}
diff --git a/vendor/go.uber.org/zap/zapcore/json_encoder.go b/vendor/go.uber.org/zap/zapcore/json_encoder.go
new file mode 100644
index 0000000..1006ba2
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/json_encoder.go
@@ -0,0 +1,480 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"math"
+	"sync"
+	"time"
+	"unicode/utf8"
+
+	"go.uber.org/zap/buffer"
+	"go.uber.org/zap/internal/bufferpool"
+)
+
+// For JSON-escaping; see jsonEncoder.safeAddString below.
+const _hex = "0123456789abcdef"
+
+var _jsonPool = sync.Pool{New: func() interface{} {
+	return &jsonEncoder{}
+}}
+
+func getJSONEncoder() *jsonEncoder {
+	return _jsonPool.Get().(*jsonEncoder)
+}
+
+func putJSONEncoder(enc *jsonEncoder) {
+	enc.EncoderConfig = nil
+	enc.buf = nil
+	enc.spaced = false
+	enc.openNamespaces = 0
+	_jsonPool.Put(enc)
+}
+
+type jsonEncoder struct {
+	*EncoderConfig
+	buf            *buffer.Buffer
+	spaced         bool // include spaces after colons and commas
+	openNamespaces int
+}
+
+// NewJSONEncoder creates a fast, low-allocation JSON encoder. The encoder
+// appropriately escapes all field keys and values.
+//
+// Note that the encoder doesn't deduplicate keys, so it's possible to produce
+// a message like
+//   {"foo":"bar","foo":"baz"}
+// This is permitted by the JSON specification, but not encouraged. Many
+// libraries will ignore duplicate key-value pairs (typically keeping the last
+// pair) when unmarshaling, but users should attempt to avoid adding duplicate
+// keys.
+func NewJSONEncoder(cfg EncoderConfig) Encoder {
+	return newJSONEncoder(cfg, false)
+}
+
+func newJSONEncoder(cfg EncoderConfig, spaced bool) *jsonEncoder {
+	return &jsonEncoder{
+		EncoderConfig: &cfg,
+		buf:           bufferpool.Get(),
+		spaced:        spaced,
+	}
+}
+
+func (enc *jsonEncoder) AddArray(key string, arr ArrayMarshaler) error {
+	enc.addKey(key)
+	return enc.AppendArray(arr)
+}
+
+func (enc *jsonEncoder) AddObject(key string, obj ObjectMarshaler) error {
+	enc.addKey(key)
+	return enc.AppendObject(obj)
+}
+
+func (enc *jsonEncoder) AddBinary(key string, val []byte) {
+	enc.AddString(key, base64.StdEncoding.EncodeToString(val))
+}
+
+func (enc *jsonEncoder) AddByteString(key string, val []byte) {
+	enc.addKey(key)
+	enc.AppendByteString(val)
+}
+
+func (enc *jsonEncoder) AddBool(key string, val bool) {
+	enc.addKey(key)
+	enc.AppendBool(val)
+}
+
+func (enc *jsonEncoder) AddComplex128(key string, val complex128) {
+	enc.addKey(key)
+	enc.AppendComplex128(val)
+}
+
+func (enc *jsonEncoder) AddDuration(key string, val time.Duration) {
+	enc.addKey(key)
+	enc.AppendDuration(val)
+}
+
+func (enc *jsonEncoder) AddFloat64(key string, val float64) {
+	enc.addKey(key)
+	enc.AppendFloat64(val)
+}
+
+func (enc *jsonEncoder) AddInt64(key string, val int64) {
+	enc.addKey(key)
+	enc.AppendInt64(val)
+}
+
+func (enc *jsonEncoder) AddReflected(key string, obj interface{}) error {
+	marshaled, err := json.Marshal(obj)
+	if err != nil {
+		return err
+	}
+	enc.addKey(key)
+	_, err = enc.buf.Write(marshaled)
+	return err
+}
+
+func (enc *jsonEncoder) OpenNamespace(key string) {
+	enc.addKey(key)
+	enc.buf.AppendByte('{')
+	enc.openNamespaces++
+}
+
+func (enc *jsonEncoder) AddString(key, val string) {
+	enc.addKey(key)
+	enc.AppendString(val)
+}
+
+func (enc *jsonEncoder) AddTime(key string, val time.Time) {
+	enc.addKey(key)
+	enc.AppendTime(val)
+}
+
+func (enc *jsonEncoder) AddUint64(key string, val uint64) {
+	enc.addKey(key)
+	enc.AppendUint64(val)
+}
+
+func (enc *jsonEncoder) AppendArray(arr ArrayMarshaler) error {
+	enc.addElementSeparator()
+	enc.buf.AppendByte('[')
+	err := arr.MarshalLogArray(enc)
+	enc.buf.AppendByte(']')
+	return err
+}
+
+func (enc *jsonEncoder) AppendObject(obj ObjectMarshaler) error {
+	enc.addElementSeparator()
+	enc.buf.AppendByte('{')
+	err := obj.MarshalLogObject(enc)
+	enc.buf.AppendByte('}')
+	return err
+}
+
+func (enc *jsonEncoder) AppendBool(val bool) {
+	enc.addElementSeparator()
+	enc.buf.AppendBool(val)
+}
+
+func (enc *jsonEncoder) AppendByteString(val []byte) {
+	enc.addElementSeparator()
+	enc.buf.AppendByte('"')
+	enc.safeAddByteString(val)
+	enc.buf.AppendByte('"')
+}
+
+func (enc *jsonEncoder) AppendComplex128(val complex128) {
+	enc.addElementSeparator()
+	// Cast to a platform-independent, fixed-size type.
+	r, i := float64(real(val)), float64(imag(val))
+	enc.buf.AppendByte('"')
+	// Because we're always in a quoted string, we can use strconv without
+	// special-casing NaN and +/-Inf.
+	enc.buf.AppendFloat(r, 64)
+	enc.buf.AppendByte('+')
+	enc.buf.AppendFloat(i, 64)
+	enc.buf.AppendByte('i')
+	enc.buf.AppendByte('"')
+}
+
+func (enc *jsonEncoder) AppendDuration(val time.Duration) {
+	cur := enc.buf.Len()
+	enc.EncodeDuration(val, enc)
+	if cur == enc.buf.Len() {
+		// User-supplied EncodeDuration is a no-op. Fall back to nanoseconds to keep
+		// JSON valid.
+		enc.AppendInt64(int64(val))
+	}
+}
+
+func (enc *jsonEncoder) AppendInt64(val int64) {
+	enc.addElementSeparator()
+	enc.buf.AppendInt(val)
+}
+
+func (enc *jsonEncoder) AppendReflected(val interface{}) error {
+	marshaled, err := json.Marshal(val)
+	if err != nil {
+		return err
+	}
+	enc.addElementSeparator()
+	_, err = enc.buf.Write(marshaled)
+	return err
+}
+
+func (enc *jsonEncoder) AppendString(val string) {
+	enc.addElementSeparator()
+	enc.buf.AppendByte('"')
+	enc.safeAddString(val)
+	enc.buf.AppendByte('"')
+}
+
+func (enc *jsonEncoder) AppendTime(val time.Time) {
+	cur := enc.buf.Len()
+	enc.EncodeTime(val, enc)
+	if cur == enc.buf.Len() {
+		// User-supplied EncodeTime is a no-op. Fall back to nanos since epoch to keep
+		// output JSON valid.
+		enc.AppendInt64(val.UnixNano())
+	}
+}
+
+func (enc *jsonEncoder) AppendUint64(val uint64) {
+	enc.addElementSeparator()
+	enc.buf.AppendUint(val)
+}
+
+func (enc *jsonEncoder) AddComplex64(k string, v complex64) { enc.AddComplex128(k, complex128(v)) }
+func (enc *jsonEncoder) AddFloat32(k string, v float32)     { enc.AddFloat64(k, float64(v)) }
+func (enc *jsonEncoder) AddInt(k string, v int)             { enc.AddInt64(k, int64(v)) }
+func (enc *jsonEncoder) AddInt32(k string, v int32)         { enc.AddInt64(k, int64(v)) }
+func (enc *jsonEncoder) AddInt16(k string, v int16)         { enc.AddInt64(k, int64(v)) }
+func (enc *jsonEncoder) AddInt8(k string, v int8)           { enc.AddInt64(k, int64(v)) }
+func (enc *jsonEncoder) AddUint(k string, v uint)           { enc.AddUint64(k, uint64(v)) }
+func (enc *jsonEncoder) AddUint32(k string, v uint32)       { enc.AddUint64(k, uint64(v)) }
+func (enc *jsonEncoder) AddUint16(k string, v uint16)       { enc.AddUint64(k, uint64(v)) }
+func (enc *jsonEncoder) AddUint8(k string, v uint8)         { enc.AddUint64(k, uint64(v)) }
+func (enc *jsonEncoder) AddUintptr(k string, v uintptr)     { enc.AddUint64(k, uint64(v)) }
+func (enc *jsonEncoder) AppendComplex64(v complex64)        { enc.AppendComplex128(complex128(v)) }
+func (enc *jsonEncoder) AppendFloat64(v float64)            { enc.appendFloat(v, 64) }
+func (enc *jsonEncoder) AppendFloat32(v float32)            { enc.appendFloat(float64(v), 32) }
+func (enc *jsonEncoder) AppendInt(v int)                    { enc.AppendInt64(int64(v)) }
+func (enc *jsonEncoder) AppendInt32(v int32)                { enc.AppendInt64(int64(v)) }
+func (enc *jsonEncoder) AppendInt16(v int16)                { enc.AppendInt64(int64(v)) }
+func (enc *jsonEncoder) AppendInt8(v int8)                  { enc.AppendInt64(int64(v)) }
+func (enc *jsonEncoder) AppendUint(v uint)                  { enc.AppendUint64(uint64(v)) }
+func (enc *jsonEncoder) AppendUint32(v uint32)              { enc.AppendUint64(uint64(v)) }
+func (enc *jsonEncoder) AppendUint16(v uint16)              { enc.AppendUint64(uint64(v)) }
+func (enc *jsonEncoder) AppendUint8(v uint8)                { enc.AppendUint64(uint64(v)) }
+func (enc *jsonEncoder) AppendUintptr(v uintptr)            { enc.AppendUint64(uint64(v)) }
+
+func (enc *jsonEncoder) Clone() Encoder {
+	clone := enc.clone()
+	clone.buf.Write(enc.buf.Bytes())
+	return clone
+}
+
+func (enc *jsonEncoder) clone() *jsonEncoder {
+	clone := getJSONEncoder()
+	clone.EncoderConfig = enc.EncoderConfig
+	clone.spaced = enc.spaced
+	clone.openNamespaces = enc.openNamespaces
+	clone.buf = bufferpool.Get()
+	return clone
+}
+
+func (enc *jsonEncoder) EncodeEntry(ent Entry, fields []Field) (*buffer.Buffer, error) {
+	final := enc.clone()
+	final.buf.AppendByte('{')
+
+	if final.LevelKey != "" {
+		final.addKey(final.LevelKey)
+		cur := final.buf.Len()
+		final.EncodeLevel(ent.Level, final)
+		if cur == final.buf.Len() {
+			// User-supplied EncodeLevel was a no-op. Fall back to strings to keep
+			// output JSON valid.
+			final.AppendString(ent.Level.String())
+		}
+	}
+	if final.TimeKey != "" {
+		final.AddTime(final.TimeKey, ent.Time)
+	}
+	if ent.LoggerName != "" && final.NameKey != "" {
+		final.addKey(final.NameKey)
+		cur := final.buf.Len()
+		nameEncoder := final.EncodeName
+
+		// if no name encoder provided, fall back to FullNameEncoder for backwards
+		// compatibility
+		if nameEncoder == nil {
+			nameEncoder = FullNameEncoder
+		}
+
+		nameEncoder(ent.LoggerName, final)
+		if cur == final.buf.Len() {
+			// User-supplied EncodeName was a no-op. Fall back to strings to
+			// keep output JSON valid.
+			final.AppendString(ent.LoggerName)
+		}
+	}
+	if ent.Caller.Defined && final.CallerKey != "" {
+		final.addKey(final.CallerKey)
+		cur := final.buf.Len()
+		final.EncodeCaller(ent.Caller, final)
+		if cur == final.buf.Len() {
+			// User-supplied EncodeCaller was a no-op. Fall back to strings to
+			// keep output JSON valid.
+			final.AppendString(ent.Caller.String())
+		}
+	}
+	if final.MessageKey != "" {
+		final.addKey(enc.MessageKey)
+		final.AppendString(ent.Message)
+	}
+	if enc.buf.Len() > 0 {
+		final.addElementSeparator()
+		final.buf.Write(enc.buf.Bytes())
+	}
+	addFields(final, fields)
+	final.closeOpenNamespaces()
+	if ent.Stack != "" && final.StacktraceKey != "" {
+		final.AddString(final.StacktraceKey, ent.Stack)
+	}
+	final.buf.AppendByte('}')
+	if final.LineEnding != "" {
+		final.buf.AppendString(final.LineEnding)
+	} else {
+		final.buf.AppendString(DefaultLineEnding)
+	}
+
+	ret := final.buf
+	putJSONEncoder(final)
+	return ret, nil
+}
+
+func (enc *jsonEncoder) truncate() {
+	enc.buf.Reset()
+}
+
+func (enc *jsonEncoder) closeOpenNamespaces() {
+	for i := 0; i < enc.openNamespaces; i++ {
+		enc.buf.AppendByte('}')
+	}
+}
+
+func (enc *jsonEncoder) addKey(key string) {
+	enc.addElementSeparator()
+	enc.buf.AppendByte('"')
+	enc.safeAddString(key)
+	enc.buf.AppendByte('"')
+	enc.buf.AppendByte(':')
+	if enc.spaced {
+		enc.buf.AppendByte(' ')
+	}
+}
+
+func (enc *jsonEncoder) addElementSeparator() {
+	last := enc.buf.Len() - 1
+	if last < 0 {
+		return
+	}
+	switch enc.buf.Bytes()[last] {
+	case '{', '[', ':', ',', ' ':
+		return
+	default:
+		enc.buf.AppendByte(',')
+		if enc.spaced {
+			enc.buf.AppendByte(' ')
+		}
+	}
+}
+
+func (enc *jsonEncoder) appendFloat(val float64, bitSize int) {
+	enc.addElementSeparator()
+	switch {
+	case math.IsNaN(val):
+		enc.buf.AppendString(`"NaN"`)
+	case math.IsInf(val, 1):
+		enc.buf.AppendString(`"+Inf"`)
+	case math.IsInf(val, -1):
+		enc.buf.AppendString(`"-Inf"`)
+	default:
+		enc.buf.AppendFloat(val, bitSize)
+	}
+}
+
+// safeAddString JSON-escapes a string and appends it to the internal buffer.
+// Unlike the standard library's encoder, it doesn't attempt to protect the
+// user from browser vulnerabilities or JSONP-related problems.
+func (enc *jsonEncoder) safeAddString(s string) {
+	for i := 0; i < len(s); {
+		if enc.tryAddRuneSelf(s[i]) {
+			i++
+			continue
+		}
+		r, size := utf8.DecodeRuneInString(s[i:])
+		if enc.tryAddRuneError(r, size) {
+			i++
+			continue
+		}
+		enc.buf.AppendString(s[i : i+size])
+		i += size
+	}
+}
+
+// safeAddByteString is no-alloc equivalent of safeAddString(string(s)) for s []byte.
+func (enc *jsonEncoder) safeAddByteString(s []byte) {
+	for i := 0; i < len(s); {
+		if enc.tryAddRuneSelf(s[i]) {
+			i++
+			continue
+		}
+		r, size := utf8.DecodeRune(s[i:])
+		if enc.tryAddRuneError(r, size) {
+			i++
+			continue
+		}
+		enc.buf.Write(s[i : i+size])
+		i += size
+	}
+}
+
+// tryAddRuneSelf appends b if it is valid UTF-8 character represented in a single byte.
+func (enc *jsonEncoder) tryAddRuneSelf(b byte) bool {
+	if b >= utf8.RuneSelf {
+		return false
+	}
+	if 0x20 <= b && b != '\\' && b != '"' {
+		enc.buf.AppendByte(b)
+		return true
+	}
+	switch b {
+	case '\\', '"':
+		enc.buf.AppendByte('\\')
+		enc.buf.AppendByte(b)
+	case '\n':
+		enc.buf.AppendByte('\\')
+		enc.buf.AppendByte('n')
+	case '\r':
+		enc.buf.AppendByte('\\')
+		enc.buf.AppendByte('r')
+	case '\t':
+		enc.buf.AppendByte('\\')
+		enc.buf.AppendByte('t')
+	default:
+		// Encode bytes < 0x20, except for the escape sequences above.
+		enc.buf.AppendString(`\u00`)
+		enc.buf.AppendByte(_hex[b>>4])
+		enc.buf.AppendByte(_hex[b&0xF])
+	}
+	return true
+}
+
+func (enc *jsonEncoder) tryAddRuneError(r rune, size int) bool {
+	if r == utf8.RuneError && size == 1 {
+		enc.buf.AppendString(`\ufffd`)
+		return true
+	}
+	return false
+}
diff --git a/vendor/go.uber.org/zap/zapcore/json_encoder_bench_test.go b/vendor/go.uber.org/zap/zapcore/json_encoder_bench_test.go
new file mode 100644
index 0000000..4bd5033
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/json_encoder_bench_test.go
@@ -0,0 +1,91 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore_test
+
+import (
+	"encoding/json"
+	"testing"
+	"time"
+
+	. "go.uber.org/zap/zapcore"
+)
+
+func BenchmarkJSONLogMarshalerFunc(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		enc := NewJSONEncoder(testEncoderConfig())
+		enc.AddObject("nested", ObjectMarshalerFunc(func(enc ObjectEncoder) error {
+			enc.AddInt64("i", int64(i))
+			return nil
+		}))
+	}
+}
+
+func BenchmarkZapJSON(b *testing.B) {
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			enc := NewJSONEncoder(testEncoderConfig())
+			enc.AddString("str", "foo")
+			enc.AddInt64("int64-1", 1)
+			enc.AddInt64("int64-2", 2)
+			enc.AddFloat64("float64", 1.0)
+			enc.AddString("string1", "\n")
+			enc.AddString("string2", "💩")
+			enc.AddString("string3", "🤔")
+			enc.AddString("string4", "🙊")
+			enc.AddBool("bool", true)
+			buf, _ := enc.EncodeEntry(Entry{
+				Message: "fake",
+				Level:   DebugLevel,
+			}, nil)
+			buf.Free()
+		}
+	})
+}
+
+func BenchmarkStandardJSON(b *testing.B) {
+	record := struct {
+		Level   string                 `json:"level"`
+		Message string                 `json:"msg"`
+		Time    time.Time              `json:"ts"`
+		Fields  map[string]interface{} `json:"fields"`
+	}{
+		Level:   "debug",
+		Message: "fake",
+		Time:    time.Unix(0, 0),
+		Fields: map[string]interface{}{
+			"str":     "foo",
+			"int64-1": int64(1),
+			"int64-2": int64(1),
+			"float64": float64(1.0),
+			"string1": "\n",
+			"string2": "💩",
+			"string3": "🤔",
+			"string4": "🙊",
+			"bool":    true,
+		},
+	}
+	b.ResetTimer()
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			json.Marshal(record)
+		}
+	})
+}
diff --git a/vendor/go.uber.org/zap/zapcore/json_encoder_impl_test.go b/vendor/go.uber.org/zap/zapcore/json_encoder_impl_test.go
new file mode 100644
index 0000000..a2dd722
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/json_encoder_impl_test.go
@@ -0,0 +1,475 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"encoding/json"
+	"errors"
+	"math"
+	"math/rand"
+	"reflect"
+	"testing"
+	"testing/quick"
+	"time"
+
+	"go.uber.org/zap/internal/bufferpool"
+
+	"github.com/stretchr/testify/assert"
+	"go.uber.org/multierr"
+)
+
+func TestJSONClone(t *testing.T) {
+	// The parent encoder is created with plenty of excess capacity.
+	parent := &jsonEncoder{buf: bufferpool.Get()}
+	clone := parent.Clone()
+
+	// Adding to the parent shouldn't affect the clone, and vice versa.
+	parent.AddString("foo", "bar")
+	clone.AddString("baz", "bing")
+
+	assertJSON(t, `"foo":"bar"`, parent)
+	assertJSON(t, `"baz":"bing"`, clone.(*jsonEncoder))
+}
+
+func TestJSONEscaping(t *testing.T) {
+	enc := &jsonEncoder{buf: bufferpool.Get()}
+	// Test all the edge cases of JSON escaping directly.
+	cases := map[string]string{
+		// ASCII.
+		`foo`: `foo`,
+		// Special-cased characters.
+		`"`: `\"`,
+		`\`: `\\`,
+		// Special-cased characters within everyday ASCII.
+		`foo"foo`: `foo\"foo`,
+		"foo\n":   `foo\n`,
+		// Special-cased control characters.
+		"\n": `\n`,
+		"\r": `\r`,
+		"\t": `\t`,
+		// \b and \f are sometimes backslash-escaped, but this representation is also
+		// conformant.
+		"\b": `\u0008`,
+		"\f": `\u000c`,
+		// The standard lib special-cases angle brackets and ampersands by default,
+		// because it wants to protect users from browser exploits. In a logging
+		// context, we shouldn't special-case these characters.
+		"<": "<",
+		">": ">",
+		"&": "&",
+		// ASCII bell - not special-cased.
+		string(byte(0x07)): `\u0007`,
+		// Astral-plane unicode.
+		`☃`: `☃`,
+		// Decodes to (RuneError, 1)
+		"\xed\xa0\x80":    `\ufffd\ufffd\ufffd`,
+		"foo\xed\xa0\x80": `foo\ufffd\ufffd\ufffd`,
+	}
+
+	t.Run("String", func(t *testing.T) {
+		for input, output := range cases {
+			enc.truncate()
+			enc.safeAddString(input)
+			assertJSON(t, output, enc)
+		}
+	})
+
+	t.Run("ByteString", func(t *testing.T) {
+		for input, output := range cases {
+			enc.truncate()
+			enc.safeAddByteString([]byte(input))
+			assertJSON(t, output, enc)
+		}
+	})
+}
+
+func TestJSONEncoderObjectFields(t *testing.T) {
+	tests := []struct {
+		desc     string
+		expected string
+		f        func(Encoder)
+	}{
+		{"binary", `"k":"YWIxMg=="`, func(e Encoder) { e.AddBinary("k", []byte("ab12")) }},
+		{"bool", `"k\\":true`, func(e Encoder) { e.AddBool(`k\`, true) }}, // test key escaping once
+		{"bool", `"k":true`, func(e Encoder) { e.AddBool("k", true) }},
+		{"bool", `"k":false`, func(e Encoder) { e.AddBool("k", false) }},
+		{"byteString", `"k":"v\\"`, func(e Encoder) { e.AddByteString(`k`, []byte(`v\`)) }},
+		{"byteString", `"k":"v"`, func(e Encoder) { e.AddByteString("k", []byte("v")) }},
+		{"byteString", `"k":""`, func(e Encoder) { e.AddByteString("k", []byte{}) }},
+		{"byteString", `"k":""`, func(e Encoder) { e.AddByteString("k", nil) }},
+		{"complex128", `"k":"1+2i"`, func(e Encoder) { e.AddComplex128("k", 1+2i) }},
+		{"complex64", `"k":"1+2i"`, func(e Encoder) { e.AddComplex64("k", 1+2i) }},
+		{"duration", `"k":0.000000001`, func(e Encoder) { e.AddDuration("k", 1) }},
+		{"float64", `"k":1`, func(e Encoder) { e.AddFloat64("k", 1.0) }},
+		{"float64", `"k":10000000000`, func(e Encoder) { e.AddFloat64("k", 1e10) }},
+		{"float64", `"k":"NaN"`, func(e Encoder) { e.AddFloat64("k", math.NaN()) }},
+		{"float64", `"k":"+Inf"`, func(e Encoder) { e.AddFloat64("k", math.Inf(1)) }},
+		{"float64", `"k":"-Inf"`, func(e Encoder) { e.AddFloat64("k", math.Inf(-1)) }},
+		{"float32", `"k":1`, func(e Encoder) { e.AddFloat32("k", 1.0) }},
+		{"float32", `"k":10000000000`, func(e Encoder) { e.AddFloat32("k", 1e10) }},
+		{"float32", `"k":"NaN"`, func(e Encoder) { e.AddFloat32("k", float32(math.NaN())) }},
+		{"float32", `"k":"+Inf"`, func(e Encoder) { e.AddFloat32("k", float32(math.Inf(1))) }},
+		{"float32", `"k":"-Inf"`, func(e Encoder) { e.AddFloat32("k", float32(math.Inf(-1))) }},
+		{"int", `"k":42`, func(e Encoder) { e.AddInt("k", 42) }},
+		{"int64", `"k":42`, func(e Encoder) { e.AddInt64("k", 42) }},
+		{"int32", `"k":42`, func(e Encoder) { e.AddInt32("k", 42) }},
+		{"int16", `"k":42`, func(e Encoder) { e.AddInt16("k", 42) }},
+		{"int8", `"k":42`, func(e Encoder) { e.AddInt8("k", 42) }},
+		{"string", `"k":"v\\"`, func(e Encoder) { e.AddString(`k`, `v\`) }},
+		{"string", `"k":"v"`, func(e Encoder) { e.AddString("k", "v") }},
+		{"string", `"k":""`, func(e Encoder) { e.AddString("k", "") }},
+		{"time", `"k":1`, func(e Encoder) { e.AddTime("k", time.Unix(1, 0)) }},
+		{"uint", `"k":42`, func(e Encoder) { e.AddUint("k", 42) }},
+		{"uint64", `"k":42`, func(e Encoder) { e.AddUint64("k", 42) }},
+		{"uint32", `"k":42`, func(e Encoder) { e.AddUint32("k", 42) }},
+		{"uint16", `"k":42`, func(e Encoder) { e.AddUint16("k", 42) }},
+		{"uint8", `"k":42`, func(e Encoder) { e.AddUint8("k", 42) }},
+		{"uintptr", `"k":42`, func(e Encoder) { e.AddUintptr("k", 42) }},
+		{
+			desc:     "object (success)",
+			expected: `"k":{"loggable":"yes"}`,
+			f: func(e Encoder) {
+				assert.NoError(t, e.AddObject("k", loggable{true}), "Unexpected error calling MarshalLogObject.")
+			},
+		},
+		{
+			desc:     "object (error)",
+			expected: `"k":{}`,
+			f: func(e Encoder) {
+				assert.Error(t, e.AddObject("k", loggable{false}), "Expected an error calling MarshalLogObject.")
+			},
+		},
+		{
+			desc:     "object (with nested array)",
+			expected: `"turducken":{"ducks":[{"in":"chicken"},{"in":"chicken"}]}`,
+			f: func(e Encoder) {
+				assert.NoError(
+					t,
+					e.AddObject("turducken", turducken{}),
+					"Unexpected error calling MarshalLogObject with nested ObjectMarshalers and ArrayMarshalers.",
+				)
+			},
+		},
+		{
+			desc:     "array (with nested object)",
+			expected: `"turduckens":[{"ducks":[{"in":"chicken"},{"in":"chicken"}]},{"ducks":[{"in":"chicken"},{"in":"chicken"}]}]`,
+			f: func(e Encoder) {
+				assert.NoError(
+					t,
+					e.AddArray("turduckens", turduckens(2)),
+					"Unexpected error calling MarshalLogObject with nested ObjectMarshalers and ArrayMarshalers.",
+				)
+			},
+		},
+		{
+			desc:     "array (success)",
+			expected: `"k":[true]`,
+			f: func(e Encoder) {
+				assert.NoError(t, e.AddArray(`k`, loggable{true}), "Unexpected error calling MarshalLogArray.")
+			},
+		},
+		{
+			desc:     "array (error)",
+			expected: `"k":[]`,
+			f: func(e Encoder) {
+				assert.Error(t, e.AddArray("k", loggable{false}), "Expected an error calling MarshalLogArray.")
+			},
+		},
+		{
+			desc:     "reflect (success)",
+			expected: `"k":{"loggable":"yes"}`,
+			f: func(e Encoder) {
+				assert.NoError(t, e.AddReflected("k", map[string]string{"loggable": "yes"}), "Unexpected error JSON-serializing a map.")
+			},
+		},
+		{
+			desc:     "reflect (failure)",
+			expected: "",
+			f: func(e Encoder) {
+				assert.Error(t, e.AddReflected("k", noJSON{}), "Unexpected success JSON-serializing a noJSON.")
+			},
+		},
+		{
+			desc: "namespace",
+			// EncodeEntry is responsible for closing all open namespaces.
+			expected: `"outermost":{"outer":{"foo":1,"inner":{"foo":2,"innermost":{`,
+			f: func(e Encoder) {
+				e.OpenNamespace("outermost")
+				e.OpenNamespace("outer")
+				e.AddInt("foo", 1)
+				e.OpenNamespace("inner")
+				e.AddInt("foo", 2)
+				e.OpenNamespace("innermost")
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		assertOutput(t, tt.desc, tt.expected, tt.f)
+	}
+}
+
+func TestJSONEncoderArrays(t *testing.T) {
+	tests := []struct {
+		desc     string
+		expected string // expect f to be called twice
+		f        func(ArrayEncoder)
+	}{
+		{"bool", `[true,true]`, func(e ArrayEncoder) { e.AppendBool(true) }},
+		{"byteString", `["k","k"]`, func(e ArrayEncoder) { e.AppendByteString([]byte("k")) }},
+		{"byteString", `["k\\","k\\"]`, func(e ArrayEncoder) { e.AppendByteString([]byte(`k\`)) }},
+		{"complex128", `["1+2i","1+2i"]`, func(e ArrayEncoder) { e.AppendComplex128(1 + 2i) }},
+		{"complex64", `["1+2i","1+2i"]`, func(e ArrayEncoder) { e.AppendComplex64(1 + 2i) }},
+		{"durations", `[0.000000002,0.000000002]`, func(e ArrayEncoder) { e.AppendDuration(2) }},
+		{"float64", `[3.14,3.14]`, func(e ArrayEncoder) { e.AppendFloat64(3.14) }},
+		{"float32", `[3.14,3.14]`, func(e ArrayEncoder) { e.AppendFloat32(3.14) }},
+		{"int", `[42,42]`, func(e ArrayEncoder) { e.AppendInt(42) }},
+		{"int64", `[42,42]`, func(e ArrayEncoder) { e.AppendInt64(42) }},
+		{"int32", `[42,42]`, func(e ArrayEncoder) { e.AppendInt32(42) }},
+		{"int16", `[42,42]`, func(e ArrayEncoder) { e.AppendInt16(42) }},
+		{"int8", `[42,42]`, func(e ArrayEncoder) { e.AppendInt8(42) }},
+		{"string", `["k","k"]`, func(e ArrayEncoder) { e.AppendString("k") }},
+		{"string", `["k\\","k\\"]`, func(e ArrayEncoder) { e.AppendString(`k\`) }},
+		{"times", `[1,1]`, func(e ArrayEncoder) { e.AppendTime(time.Unix(1, 0)) }},
+		{"uint", `[42,42]`, func(e ArrayEncoder) { e.AppendUint(42) }},
+		{"uint64", `[42,42]`, func(e ArrayEncoder) { e.AppendUint64(42) }},
+		{"uint32", `[42,42]`, func(e ArrayEncoder) { e.AppendUint32(42) }},
+		{"uint16", `[42,42]`, func(e ArrayEncoder) { e.AppendUint16(42) }},
+		{"uint8", `[42,42]`, func(e ArrayEncoder) { e.AppendUint8(42) }},
+		{"uintptr", `[42,42]`, func(e ArrayEncoder) { e.AppendUintptr(42) }},
+		{
+			desc:     "arrays (success)",
+			expected: `[[true],[true]]`,
+			f: func(arr ArrayEncoder) {
+				assert.NoError(t, arr.AppendArray(ArrayMarshalerFunc(func(inner ArrayEncoder) error {
+					inner.AppendBool(true)
+					return nil
+				})), "Unexpected error appending an array.")
+			},
+		},
+		{
+			desc:     "arrays (error)",
+			expected: `[[true],[true]]`,
+			f: func(arr ArrayEncoder) {
+				assert.Error(t, arr.AppendArray(ArrayMarshalerFunc(func(inner ArrayEncoder) error {
+					inner.AppendBool(true)
+					return errors.New("fail")
+				})), "Expected an error appending an array.")
+			},
+		},
+		{
+			desc:     "objects (success)",
+			expected: `[{"loggable":"yes"},{"loggable":"yes"}]`,
+			f: func(arr ArrayEncoder) {
+				assert.NoError(t, arr.AppendObject(loggable{true}), "Unexpected error appending an object.")
+			},
+		},
+		{
+			desc:     "objects (error)",
+			expected: `[{},{}]`,
+			f: func(arr ArrayEncoder) {
+				assert.Error(t, arr.AppendObject(loggable{false}), "Expected an error appending an object.")
+			},
+		},
+		{
+			desc:     "reflect (success)",
+			expected: `[{"foo":5},{"foo":5}]`,
+			f: func(arr ArrayEncoder) {
+				assert.NoError(
+					t,
+					arr.AppendReflected(map[string]int{"foo": 5}),
+					"Unexpected an error appending an object with reflection.",
+				)
+			},
+		},
+		{
+			desc:     "reflect (error)",
+			expected: `[]`,
+			f: func(arr ArrayEncoder) {
+				assert.Error(
+					t,
+					arr.AppendReflected(noJSON{}),
+					"Unexpected an error appending an object with reflection.",
+				)
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		f := func(enc Encoder) error {
+			return enc.AddArray("array", ArrayMarshalerFunc(func(arr ArrayEncoder) error {
+				tt.f(arr)
+				tt.f(arr)
+				return nil
+			}))
+		}
+		assertOutput(t, tt.desc, `"array":`+tt.expected, func(enc Encoder) {
+			err := f(enc)
+			assert.NoError(t, err, "Unexpected error adding array to JSON encoder.")
+		})
+	}
+}
+
+func assertJSON(t *testing.T, expected string, enc *jsonEncoder) {
+	assert.Equal(t, expected, enc.buf.String(), "Encoded JSON didn't match expectations.")
+}
+
+func assertOutput(t testing.TB, desc string, expected string, f func(Encoder)) {
+	enc := &jsonEncoder{buf: bufferpool.Get(), EncoderConfig: &EncoderConfig{
+		EncodeTime:     EpochTimeEncoder,
+		EncodeDuration: SecondsDurationEncoder,
+	}}
+	f(enc)
+	assert.Equal(t, expected, enc.buf.String(), "Unexpected encoder output after adding a %s.", desc)
+
+	enc.truncate()
+	enc.AddString("foo", "bar")
+	f(enc)
+	expectedPrefix := `"foo":"bar"`
+	if expected != "" {
+		// If we expect output, it should be comma-separated from the previous
+		// field.
+		expectedPrefix += ","
+	}
+	assert.Equal(t, expectedPrefix+expected, enc.buf.String(), "Unexpected encoder output after adding a %s as a second field.", desc)
+}
+
+// Nested Array- and ObjectMarshalers.
+type turducken struct{}
+
+func (t turducken) MarshalLogObject(enc ObjectEncoder) error {
+	return enc.AddArray("ducks", ArrayMarshalerFunc(func(arr ArrayEncoder) error {
+		for i := 0; i < 2; i++ {
+			arr.AppendObject(ObjectMarshalerFunc(func(inner ObjectEncoder) error {
+				inner.AddString("in", "chicken")
+				return nil
+			}))
+		}
+		return nil
+	}))
+}
+
+type turduckens int
+
+func (t turduckens) MarshalLogArray(enc ArrayEncoder) error {
+	var err error
+	tur := turducken{}
+	for i := 0; i < int(t); i++ {
+		err = multierr.Append(err, enc.AppendObject(tur))
+	}
+	return err
+}
+
+type loggable struct{ bool }
+
+func (l loggable) MarshalLogObject(enc ObjectEncoder) error {
+	if !l.bool {
+		return errors.New("can't marshal")
+	}
+	enc.AddString("loggable", "yes")
+	return nil
+}
+
+func (l loggable) MarshalLogArray(enc ArrayEncoder) error {
+	if !l.bool {
+		return errors.New("can't marshal")
+	}
+	enc.AppendBool(true)
+	return nil
+}
+
+type noJSON struct{}
+
+func (nj noJSON) MarshalJSON() ([]byte, error) {
+	return nil, errors.New("no")
+}
+
+func zapEncode(encode func(*jsonEncoder, string)) func(s string) []byte {
+	return func(s string) []byte {
+		enc := &jsonEncoder{buf: bufferpool.Get()}
+		// Escape and quote a string using our encoder.
+		var ret []byte
+		encode(enc, s)
+		ret = make([]byte, 0, enc.buf.Len()+2)
+		ret = append(ret, '"')
+		ret = append(ret, enc.buf.Bytes()...)
+		ret = append(ret, '"')
+		return ret
+	}
+}
+
+func roundTripsCorrectly(encode func(string) []byte, original string) bool {
+	// Encode using our encoder, decode using the standard library, and assert
+	// that we haven't lost any information.
+	encoded := encode(original)
+
+	var decoded string
+	err := json.Unmarshal(encoded, &decoded)
+	if err != nil {
+		return false
+	}
+	return original == decoded
+}
+
+func roundTripsCorrectlyString(original string) bool {
+	return roundTripsCorrectly(zapEncode((*jsonEncoder).safeAddString), original)
+}
+
+func roundTripsCorrectlyByteString(original string) bool {
+	return roundTripsCorrectly(
+		zapEncode(func(enc *jsonEncoder, s string) {
+			enc.safeAddByteString([]byte(s))
+		}),
+		original)
+}
+
+type ASCII string
+
+func (s ASCII) Generate(r *rand.Rand, size int) reflect.Value {
+	bs := make([]byte, size)
+	for i := range bs {
+		bs[i] = byte(r.Intn(128))
+	}
+	a := ASCII(bs)
+	return reflect.ValueOf(a)
+}
+
+func asciiRoundTripsCorrectlyString(s ASCII) bool {
+	return roundTripsCorrectlyString(string(s))
+}
+
+func asciiRoundTripsCorrectlyByteString(s ASCII) bool {
+	return roundTripsCorrectlyByteString(string(s))
+}
+
+func TestJSONQuick(t *testing.T) {
+	check := func(f interface{}) {
+		err := quick.Check(f, &quick.Config{MaxCountScale: 100.0})
+		assert.NoError(t, err)
+	}
+	// Test the full range of UTF-8 strings.
+	check(roundTripsCorrectlyString)
+	check(roundTripsCorrectlyByteString)
+
+	// Focus on ASCII strings.
+	check(asciiRoundTripsCorrectlyString)
+	check(asciiRoundTripsCorrectlyByteString)
+}
diff --git a/vendor/go.uber.org/zap/zapcore/level.go b/vendor/go.uber.org/zap/zapcore/level.go
new file mode 100644
index 0000000..e575c9f
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/level.go
@@ -0,0 +1,175 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+)
+
+var errUnmarshalNilLevel = errors.New("can't unmarshal a nil *Level")
+
+// A Level is a logging priority. Higher levels are more important.
+type Level int8
+
+const (
+	// DebugLevel logs are typically voluminous, and are usually disabled in
+	// production.
+	DebugLevel Level = iota - 1
+	// InfoLevel is the default logging priority.
+	InfoLevel
+	// WarnLevel logs are more important than Info, but don't need individual
+	// human review.
+	WarnLevel
+	// ErrorLevel logs are high-priority. If an application is running smoothly,
+	// it shouldn't generate any error-level logs.
+	ErrorLevel
+	// DPanicLevel logs are particularly important errors. In development the
+	// logger panics after writing the message.
+	DPanicLevel
+	// PanicLevel logs a message, then panics.
+	PanicLevel
+	// FatalLevel logs a message, then calls os.Exit(1).
+	FatalLevel
+
+	_minLevel = DebugLevel
+	_maxLevel = FatalLevel
+)
+
+// String returns a lower-case ASCII representation of the log level.
+func (l Level) String() string {
+	switch l {
+	case DebugLevel:
+		return "debug"
+	case InfoLevel:
+		return "info"
+	case WarnLevel:
+		return "warn"
+	case ErrorLevel:
+		return "error"
+	case DPanicLevel:
+		return "dpanic"
+	case PanicLevel:
+		return "panic"
+	case FatalLevel:
+		return "fatal"
+	default:
+		return fmt.Sprintf("Level(%d)", l)
+	}
+}
+
+// CapitalString returns an all-caps ASCII representation of the log level.
+func (l Level) CapitalString() string {
+	// Printing levels in all-caps is common enough that we should export this
+	// functionality.
+	switch l {
+	case DebugLevel:
+		return "DEBUG"
+	case InfoLevel:
+		return "INFO"
+	case WarnLevel:
+		return "WARN"
+	case ErrorLevel:
+		return "ERROR"
+	case DPanicLevel:
+		return "DPANIC"
+	case PanicLevel:
+		return "PANIC"
+	case FatalLevel:
+		return "FATAL"
+	default:
+		return fmt.Sprintf("LEVEL(%d)", l)
+	}
+}
+
+// MarshalText marshals the Level to text. Note that the text representation
+// drops the -Level suffix (see example).
+func (l Level) MarshalText() ([]byte, error) {
+	return []byte(l.String()), nil
+}
+
+// UnmarshalText unmarshals text to a level. Like MarshalText, UnmarshalText
+// expects the text representation of a Level to drop the -Level suffix (see
+// example).
+//
+// In particular, this makes it easy to configure logging levels using YAML,
+// TOML, or JSON files.
+func (l *Level) UnmarshalText(text []byte) error {
+	if l == nil {
+		return errUnmarshalNilLevel
+	}
+	if !l.unmarshalText(text) && !l.unmarshalText(bytes.ToLower(text)) {
+		return fmt.Errorf("unrecognized level: %q", text)
+	}
+	return nil
+}
+
+func (l *Level) unmarshalText(text []byte) bool {
+	switch string(text) {
+	case "debug", "DEBUG":
+		*l = DebugLevel
+	case "info", "INFO", "": // make the zero value useful
+		*l = InfoLevel
+	case "warn", "WARN":
+		*l = WarnLevel
+	case "error", "ERROR":
+		*l = ErrorLevel
+	case "dpanic", "DPANIC":
+		*l = DPanicLevel
+	case "panic", "PANIC":
+		*l = PanicLevel
+	case "fatal", "FATAL":
+		*l = FatalLevel
+	default:
+		return false
+	}
+	return true
+}
+
+// Set sets the level for the flag.Value interface.
+func (l *Level) Set(s string) error {
+	return l.UnmarshalText([]byte(s))
+}
+
+// Get gets the level for the flag.Getter interface.
+func (l *Level) Get() interface{} {
+	return *l
+}
+
+// Enabled returns true if the given level is at or above this level.
+func (l Level) Enabled(lvl Level) bool {
+	return lvl >= l
+}
+
+// LevelEnabler decides whether a given logging level is enabled when logging a
+// message.
+//
+// Enablers are intended to be used to implement deterministic filters;
+// concerns like sampling are better implemented as a Core.
+//
+// Each concrete Level value implements a static LevelEnabler which returns
+// true for itself and all higher logging levels. For example WarnLevel.Enabled()
+// will return true for WarnLevel, ErrorLevel, DPanicLevel, PanicLevel, and
+// FatalLevel, but return false for InfoLevel and DebugLevel.
+type LevelEnabler interface {
+	Enabled(Level) bool
+}
diff --git a/vendor/go.uber.org/zap/zapcore/level_strings.go b/vendor/go.uber.org/zap/zapcore/level_strings.go
new file mode 100644
index 0000000..7af8dad
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/level_strings.go
@@ -0,0 +1,46 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import "go.uber.org/zap/internal/color"
+
+var (
+	_levelToColor = map[Level]color.Color{
+		DebugLevel:  color.Magenta,
+		InfoLevel:   color.Blue,
+		WarnLevel:   color.Yellow,
+		ErrorLevel:  color.Red,
+		DPanicLevel: color.Red,
+		PanicLevel:  color.Red,
+		FatalLevel:  color.Red,
+	}
+	_unknownLevelColor = color.Red
+
+	_levelToLowercaseColorString = make(map[Level]string, len(_levelToColor))
+	_levelToCapitalColorString   = make(map[Level]string, len(_levelToColor))
+)
+
+func init() {
+	for level, color := range _levelToColor {
+		_levelToLowercaseColorString[level] = color.Add(level.String())
+		_levelToCapitalColorString[level] = color.Add(level.CapitalString())
+	}
+}
diff --git a/vendor/go.uber.org/zap/zapcore/level_strings_test.go b/vendor/go.uber.org/zap/zapcore/level_strings_test.go
new file mode 100644
index 0000000..14b0bac
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/level_strings_test.go
@@ -0,0 +1,38 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAllLevelsCoveredByLevelString(t *testing.T) {
+	numLevels := int((_maxLevel - _minLevel) + 1)
+
+	isComplete := func(m map[Level]string) bool {
+		return len(m) == numLevels
+	}
+
+	assert.True(t, isComplete(_levelToLowercaseColorString), "Colored lowercase strings don't cover all levels.")
+	assert.True(t, isComplete(_levelToCapitalColorString), "Colored capital strings don't cover all levels.")
+}
diff --git a/vendor/go.uber.org/zap/zapcore/level_test.go b/vendor/go.uber.org/zap/zapcore/level_test.go
new file mode 100644
index 0000000..28b75b3
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/level_test.go
@@ -0,0 +1,177 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"bytes"
+	"flag"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestLevelString(t *testing.T) {
+	tests := map[Level]string{
+		DebugLevel:  "debug",
+		InfoLevel:   "info",
+		WarnLevel:   "warn",
+		ErrorLevel:  "error",
+		DPanicLevel: "dpanic",
+		PanicLevel:  "panic",
+		FatalLevel:  "fatal",
+		Level(-42):  "Level(-42)",
+	}
+
+	for lvl, stringLevel := range tests {
+		assert.Equal(t, stringLevel, lvl.String(), "Unexpected lowercase level string.")
+		assert.Equal(t, strings.ToUpper(stringLevel), lvl.CapitalString(), "Unexpected all-caps level string.")
+	}
+}
+
+func TestLevelText(t *testing.T) {
+	tests := []struct {
+		text  string
+		level Level
+	}{
+		{"debug", DebugLevel},
+		{"info", InfoLevel},
+		{"", InfoLevel}, // make the zero value useful
+		{"warn", WarnLevel},
+		{"error", ErrorLevel},
+		{"dpanic", DPanicLevel},
+		{"panic", PanicLevel},
+		{"fatal", FatalLevel},
+	}
+	for _, tt := range tests {
+		if tt.text != "" {
+			lvl := tt.level
+			marshaled, err := lvl.MarshalText()
+			assert.NoError(t, err, "Unexpected error marshaling level %v to text.", &lvl)
+			assert.Equal(t, tt.text, string(marshaled), "Marshaling level %v to text yielded unexpected result.", &lvl)
+		}
+
+		var unmarshaled Level
+		err := unmarshaled.UnmarshalText([]byte(tt.text))
+		assert.NoError(t, err, `Unexpected error unmarshaling text %q to level.`, tt.text)
+		assert.Equal(t, tt.level, unmarshaled, `Text %q unmarshaled to an unexpected level.`, tt.text)
+	}
+}
+
+func TestCapitalLevelsParse(t *testing.T) {
+	tests := []struct {
+		text  string
+		level Level
+	}{
+		{"DEBUG", DebugLevel},
+		{"INFO", InfoLevel},
+		{"WARN", WarnLevel},
+		{"ERROR", ErrorLevel},
+		{"DPANIC", DPanicLevel},
+		{"PANIC", PanicLevel},
+		{"FATAL", FatalLevel},
+	}
+	for _, tt := range tests {
+		var unmarshaled Level
+		err := unmarshaled.UnmarshalText([]byte(tt.text))
+		assert.NoError(t, err, `Unexpected error unmarshaling text %q to level.`, tt.text)
+		assert.Equal(t, tt.level, unmarshaled, `Text %q unmarshaled to an unexpected level.`, tt.text)
+	}
+}
+
+func TestWeirdLevelsParse(t *testing.T) {
+	tests := []struct {
+		text  string
+		level Level
+	}{
+		// I guess...
+		{"Debug", DebugLevel},
+		{"Info", InfoLevel},
+		{"Warn", WarnLevel},
+		{"Error", ErrorLevel},
+		{"Dpanic", DPanicLevel},
+		{"Panic", PanicLevel},
+		{"Fatal", FatalLevel},
+
+		// What even is...
+		{"DeBuG", DebugLevel},
+		{"InFo", InfoLevel},
+		{"WaRn", WarnLevel},
+		{"ErRor", ErrorLevel},
+		{"DpAnIc", DPanicLevel},
+		{"PaNiC", PanicLevel},
+		{"FaTaL", FatalLevel},
+	}
+	for _, tt := range tests {
+		var unmarshaled Level
+		err := unmarshaled.UnmarshalText([]byte(tt.text))
+		assert.NoError(t, err, `Unexpected error unmarshaling text %q to level.`, tt.text)
+		assert.Equal(t, tt.level, unmarshaled, `Text %q unmarshaled to an unexpected level.`, tt.text)
+	}
+}
+
+func TestLevelNils(t *testing.T) {
+	var l *Level
+
+	// The String() method will not handle nil level properly.
+	assert.Panics(t, func() {
+		assert.Equal(t, "Level(nil)", l.String(), "Unexpected result stringifying nil *Level.")
+	}, "Level(nil).String() should panic")
+
+	assert.Panics(t, func() {
+		l.MarshalText()
+	}, "Expected to panic when marshalling a nil level.")
+
+	err := l.UnmarshalText([]byte("debug"))
+	assert.Equal(t, errUnmarshalNilLevel, err, "Expected to error unmarshalling into a nil Level.")
+}
+
+func TestLevelUnmarshalUnknownText(t *testing.T) {
+	var l Level
+	err := l.UnmarshalText([]byte("foo"))
+	assert.Contains(t, err.Error(), "unrecognized level", "Expected unmarshaling arbitrary text to fail.")
+}
+
+func TestLevelAsFlagValue(t *testing.T) {
+	var (
+		buf bytes.Buffer
+		lvl Level
+	)
+	fs := flag.NewFlagSet("levelTest", flag.ContinueOnError)
+	fs.SetOutput(&buf)
+	fs.Var(&lvl, "level", "log level")
+
+	for _, expected := range []Level{DebugLevel, InfoLevel, WarnLevel, ErrorLevel, DPanicLevel, PanicLevel, FatalLevel} {
+		assert.NoError(t, fs.Parse([]string{"-level", expected.String()}))
+		assert.Equal(t, expected, lvl, "Unexpected level after parsing flag.")
+		assert.Equal(t, expected, lvl.Get(), "Unexpected output using flag.Getter API.")
+		assert.Empty(t, buf.String(), "Unexpected error output parsing level flag.")
+		buf.Reset()
+	}
+
+	assert.Error(t, fs.Parse([]string{"-level", "nope"}))
+	assert.Equal(
+		t,
+		`invalid value "nope" for flag -level: unrecognized level: "nope"`,
+		strings.Split(buf.String(), "\n")[0], // second line is help message
+		"Unexpected error output from invalid flag input.",
+	)
+}
diff --git a/vendor/go.uber.org/zap/zapcore/marshaler.go b/vendor/go.uber.org/zap/zapcore/marshaler.go
new file mode 100644
index 0000000..2627a65
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/marshaler.go
@@ -0,0 +1,53 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+// ObjectMarshaler allows user-defined types to efficiently add themselves to the
+// logging context, and to selectively omit information which shouldn't be
+// included in logs (e.g., passwords).
+type ObjectMarshaler interface {
+	MarshalLogObject(ObjectEncoder) error
+}
+
+// ObjectMarshalerFunc is a type adapter that turns a function into an
+// ObjectMarshaler.
+type ObjectMarshalerFunc func(ObjectEncoder) error
+
+// MarshalLogObject calls the underlying function.
+func (f ObjectMarshalerFunc) MarshalLogObject(enc ObjectEncoder) error {
+	return f(enc)
+}
+
+// ArrayMarshaler allows user-defined types to efficiently add themselves to the
+// logging context, and to selectively omit information which shouldn't be
+// included in logs (e.g., passwords).
+type ArrayMarshaler interface {
+	MarshalLogArray(ArrayEncoder) error
+}
+
+// ArrayMarshalerFunc is a type adapter that turns a function into an
+// ArrayMarshaler.
+type ArrayMarshalerFunc func(ArrayEncoder) error
+
+// MarshalLogArray calls the underlying function.
+func (f ArrayMarshalerFunc) MarshalLogArray(enc ArrayEncoder) error {
+	return f(enc)
+}
diff --git a/vendor/go.uber.org/zap/zapcore/memory_encoder.go b/vendor/go.uber.org/zap/zapcore/memory_encoder.go
new file mode 100644
index 0000000..5c46bc1
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/memory_encoder.go
@@ -0,0 +1,179 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import "time"
+
+// MapObjectEncoder is an ObjectEncoder backed by a simple
+// map[string]interface{}. It's not fast enough for production use, but it's
+// helpful in tests.
+type MapObjectEncoder struct {
+	// Fields contains the entire encoded log context.
+	Fields map[string]interface{}
+	// cur is a pointer to the namespace we're currently writing to.
+	cur map[string]interface{}
+}
+
+// NewMapObjectEncoder creates a new map-backed ObjectEncoder.
+func NewMapObjectEncoder() *MapObjectEncoder {
+	m := make(map[string]interface{})
+	return &MapObjectEncoder{
+		Fields: m,
+		cur:    m,
+	}
+}
+
+// AddArray implements ObjectEncoder.
+func (m *MapObjectEncoder) AddArray(key string, v ArrayMarshaler) error {
+	arr := &sliceArrayEncoder{}
+	err := v.MarshalLogArray(arr)
+	m.cur[key] = arr.elems
+	return err
+}
+
+// AddObject implements ObjectEncoder.
+func (m *MapObjectEncoder) AddObject(k string, v ObjectMarshaler) error {
+	newMap := NewMapObjectEncoder()
+	m.cur[k] = newMap.Fields
+	return v.MarshalLogObject(newMap)
+}
+
+// AddBinary implements ObjectEncoder.
+func (m *MapObjectEncoder) AddBinary(k string, v []byte) { m.cur[k] = v }
+
+// AddByteString implements ObjectEncoder.
+func (m *MapObjectEncoder) AddByteString(k string, v []byte) { m.cur[k] = string(v) }
+
+// AddBool implements ObjectEncoder.
+func (m *MapObjectEncoder) AddBool(k string, v bool) { m.cur[k] = v }
+
+// AddDuration implements ObjectEncoder.
+func (m MapObjectEncoder) AddDuration(k string, v time.Duration) { m.cur[k] = v }
+
+// AddComplex128 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddComplex128(k string, v complex128) { m.cur[k] = v }
+
+// AddComplex64 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddComplex64(k string, v complex64) { m.cur[k] = v }
+
+// AddFloat64 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddFloat64(k string, v float64) { m.cur[k] = v }
+
+// AddFloat32 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddFloat32(k string, v float32) { m.cur[k] = v }
+
+// AddInt implements ObjectEncoder.
+func (m *MapObjectEncoder) AddInt(k string, v int) { m.cur[k] = v }
+
+// AddInt64 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddInt64(k string, v int64) { m.cur[k] = v }
+
+// AddInt32 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddInt32(k string, v int32) { m.cur[k] = v }
+
+// AddInt16 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddInt16(k string, v int16) { m.cur[k] = v }
+
+// AddInt8 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddInt8(k string, v int8) { m.cur[k] = v }
+
+// AddString implements ObjectEncoder.
+func (m *MapObjectEncoder) AddString(k string, v string) { m.cur[k] = v }
+
+// AddTime implements ObjectEncoder.
+func (m MapObjectEncoder) AddTime(k string, v time.Time) { m.cur[k] = v }
+
+// AddUint implements ObjectEncoder.
+func (m *MapObjectEncoder) AddUint(k string, v uint) { m.cur[k] = v }
+
+// AddUint64 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddUint64(k string, v uint64) { m.cur[k] = v }
+
+// AddUint32 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddUint32(k string, v uint32) { m.cur[k] = v }
+
+// AddUint16 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddUint16(k string, v uint16) { m.cur[k] = v }
+
+// AddUint8 implements ObjectEncoder.
+func (m *MapObjectEncoder) AddUint8(k string, v uint8) { m.cur[k] = v }
+
+// AddUintptr implements ObjectEncoder.
+func (m *MapObjectEncoder) AddUintptr(k string, v uintptr) { m.cur[k] = v }
+
+// AddReflected implements ObjectEncoder.
+func (m *MapObjectEncoder) AddReflected(k string, v interface{}) error {
+	m.cur[k] = v
+	return nil
+}
+
+// OpenNamespace implements ObjectEncoder.
+func (m *MapObjectEncoder) OpenNamespace(k string) {
+	ns := make(map[string]interface{})
+	m.cur[k] = ns
+	m.cur = ns
+}
+
+// sliceArrayEncoder is an ArrayEncoder backed by a simple []interface{}. Like
+// the MapObjectEncoder, it's not designed for production use.
+type sliceArrayEncoder struct {
+	elems []interface{}
+}
+
+func (s *sliceArrayEncoder) AppendArray(v ArrayMarshaler) error {
+	enc := &sliceArrayEncoder{}
+	err := v.MarshalLogArray(enc)
+	s.elems = append(s.elems, enc.elems)
+	return err
+}
+
+func (s *sliceArrayEncoder) AppendObject(v ObjectMarshaler) error {
+	m := NewMapObjectEncoder()
+	err := v.MarshalLogObject(m)
+	s.elems = append(s.elems, m.Fields)
+	return err
+}
+
+func (s *sliceArrayEncoder) AppendReflected(v interface{}) error {
+	s.elems = append(s.elems, v)
+	return nil
+}
+
+func (s *sliceArrayEncoder) AppendBool(v bool)              { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendByteString(v []byte)      { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendComplex128(v complex128)  { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendComplex64(v complex64)    { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendDuration(v time.Duration) { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendFloat64(v float64)        { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendFloat32(v float32)        { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendInt(v int)                { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendInt64(v int64)            { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendInt32(v int32)            { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendInt16(v int16)            { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendInt8(v int8)              { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendString(v string)          { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendTime(v time.Time)         { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendUint(v uint)              { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendUint64(v uint64)          { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendUint32(v uint32)          { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendUint16(v uint16)          { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendUint8(v uint8)            { s.elems = append(s.elems, v) }
+func (s *sliceArrayEncoder) AppendUintptr(v uintptr)        { s.elems = append(s.elems, v) }
diff --git a/vendor/go.uber.org/zap/zapcore/memory_encoder_test.go b/vendor/go.uber.org/zap/zapcore/memory_encoder_test.go
new file mode 100644
index 0000000..e63454a
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/memory_encoder_test.go
@@ -0,0 +1,283 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMapObjectEncoderAdd(t *testing.T) {
+	// Expected output of a turducken.
+	wantTurducken := map[string]interface{}{
+		"ducks": []interface{}{
+			map[string]interface{}{"in": "chicken"},
+			map[string]interface{}{"in": "chicken"},
+		},
+	}
+
+	tests := []struct {
+		desc     string
+		f        func(ObjectEncoder)
+		expected interface{}
+	}{
+		{
+			desc: "AddObject",
+			f: func(e ObjectEncoder) {
+				assert.NoError(t, e.AddObject("k", loggable{true}), "Expected AddObject to succeed.")
+			},
+			expected: map[string]interface{}{"loggable": "yes"},
+		},
+		{
+			desc: "AddObject (nested)",
+			f: func(e ObjectEncoder) {
+				assert.NoError(t, e.AddObject("k", turducken{}), "Expected AddObject to succeed.")
+			},
+			expected: wantTurducken,
+		},
+		{
+			desc: "AddArray",
+			f: func(e ObjectEncoder) {
+				assert.NoError(t, e.AddArray("k", ArrayMarshalerFunc(func(arr ArrayEncoder) error {
+					arr.AppendBool(true)
+					arr.AppendBool(false)
+					arr.AppendBool(true)
+					return nil
+				})), "Expected AddArray to succeed.")
+			},
+			expected: []interface{}{true, false, true},
+		},
+		{
+			desc: "AddArray (nested)",
+			f: func(e ObjectEncoder) {
+				assert.NoError(t, e.AddArray("k", turduckens(2)), "Expected AddArray to succeed.")
+			},
+			expected: []interface{}{wantTurducken, wantTurducken},
+		},
+		{
+			desc:     "AddBinary",
+			f:        func(e ObjectEncoder) { e.AddBinary("k", []byte("foo")) },
+			expected: []byte("foo"),
+		},
+		{
+			desc:     "AddBool",
+			f:        func(e ObjectEncoder) { e.AddBool("k", true) },
+			expected: true,
+		},
+		{
+			desc:     "AddComplex128",
+			f:        func(e ObjectEncoder) { e.AddComplex128("k", 1+2i) },
+			expected: 1 + 2i,
+		},
+		{
+			desc:     "AddComplex64",
+			f:        func(e ObjectEncoder) { e.AddComplex64("k", 1+2i) },
+			expected: complex64(1 + 2i),
+		},
+		{
+			desc:     "AddDuration",
+			f:        func(e ObjectEncoder) { e.AddDuration("k", time.Millisecond) },
+			expected: time.Millisecond,
+		},
+		{
+			desc:     "AddFloat64",
+			f:        func(e ObjectEncoder) { e.AddFloat64("k", 3.14) },
+			expected: 3.14,
+		},
+		{
+			desc:     "AddFloat32",
+			f:        func(e ObjectEncoder) { e.AddFloat32("k", 3.14) },
+			expected: float32(3.14),
+		},
+		{
+			desc:     "AddInt",
+			f:        func(e ObjectEncoder) { e.AddInt("k", 42) },
+			expected: 42,
+		},
+		{
+			desc:     "AddInt64",
+			f:        func(e ObjectEncoder) { e.AddInt64("k", 42) },
+			expected: int64(42),
+		},
+		{
+			desc:     "AddInt32",
+			f:        func(e ObjectEncoder) { e.AddInt32("k", 42) },
+			expected: int32(42),
+		},
+		{
+			desc:     "AddInt16",
+			f:        func(e ObjectEncoder) { e.AddInt16("k", 42) },
+			expected: int16(42),
+		},
+		{
+			desc:     "AddInt8",
+			f:        func(e ObjectEncoder) { e.AddInt8("k", 42) },
+			expected: int8(42),
+		},
+		{
+			desc:     "AddString",
+			f:        func(e ObjectEncoder) { e.AddString("k", "v") },
+			expected: "v",
+		},
+		{
+			desc:     "AddTime",
+			f:        func(e ObjectEncoder) { e.AddTime("k", time.Unix(0, 100)) },
+			expected: time.Unix(0, 100),
+		},
+		{
+			desc:     "AddUint",
+			f:        func(e ObjectEncoder) { e.AddUint("k", 42) },
+			expected: uint(42),
+		},
+		{
+			desc:     "AddUint64",
+			f:        func(e ObjectEncoder) { e.AddUint64("k", 42) },
+			expected: uint64(42),
+		},
+		{
+			desc:     "AddUint32",
+			f:        func(e ObjectEncoder) { e.AddUint32("k", 42) },
+			expected: uint32(42),
+		},
+		{
+			desc:     "AddUint16",
+			f:        func(e ObjectEncoder) { e.AddUint16("k", 42) },
+			expected: uint16(42),
+		},
+		{
+			desc:     "AddUint8",
+			f:        func(e ObjectEncoder) { e.AddUint8("k", 42) },
+			expected: uint8(42),
+		},
+		{
+			desc:     "AddUintptr",
+			f:        func(e ObjectEncoder) { e.AddUintptr("k", 42) },
+			expected: uintptr(42),
+		},
+		{
+			desc: "AddReflected",
+			f: func(e ObjectEncoder) {
+				assert.NoError(t, e.AddReflected("k", map[string]interface{}{"foo": 5}), "Expected AddReflected to succeed.")
+			},
+			expected: map[string]interface{}{"foo": 5},
+		},
+		{
+			desc: "OpenNamespace",
+			f: func(e ObjectEncoder) {
+				e.OpenNamespace("k")
+				e.AddInt("foo", 1)
+				e.OpenNamespace("middle")
+				e.AddInt("foo", 2)
+				e.OpenNamespace("inner")
+				e.AddInt("foo", 3)
+			},
+			expected: map[string]interface{}{
+				"foo": 1,
+				"middle": map[string]interface{}{
+					"foo": 2,
+					"inner": map[string]interface{}{
+						"foo": 3,
+					},
+				},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		enc := NewMapObjectEncoder()
+		tt.f(enc)
+		assert.Equal(t, tt.expected, enc.Fields["k"], "Unexpected encoder output.")
+	}
+}
+func TestSliceArrayEncoderAppend(t *testing.T) {
+	tests := []struct {
+		desc     string
+		f        func(ArrayEncoder)
+		expected interface{}
+	}{
+		// AppendObject and AppendArray are covered by the AddObject (nested) and
+		// AddArray (nested) cases above.
+		{"AppendBool", func(e ArrayEncoder) { e.AppendBool(true) }, true},
+		{"AppendComplex128", func(e ArrayEncoder) { e.AppendComplex128(1 + 2i) }, 1 + 2i},
+		{"AppendComplex64", func(e ArrayEncoder) { e.AppendComplex64(1 + 2i) }, complex64(1 + 2i)},
+		{"AppendDuration", func(e ArrayEncoder) { e.AppendDuration(time.Second) }, time.Second},
+		{"AppendFloat64", func(e ArrayEncoder) { e.AppendFloat64(3.14) }, 3.14},
+		{"AppendFloat32", func(e ArrayEncoder) { e.AppendFloat32(3.14) }, float32(3.14)},
+		{"AppendInt", func(e ArrayEncoder) { e.AppendInt(42) }, 42},
+		{"AppendInt64", func(e ArrayEncoder) { e.AppendInt64(42) }, int64(42)},
+		{"AppendInt32", func(e ArrayEncoder) { e.AppendInt32(42) }, int32(42)},
+		{"AppendInt16", func(e ArrayEncoder) { e.AppendInt16(42) }, int16(42)},
+		{"AppendInt8", func(e ArrayEncoder) { e.AppendInt8(42) }, int8(42)},
+		{"AppendString", func(e ArrayEncoder) { e.AppendString("foo") }, "foo"},
+		{"AppendTime", func(e ArrayEncoder) { e.AppendTime(time.Unix(0, 100)) }, time.Unix(0, 100)},
+		{"AppendUint", func(e ArrayEncoder) { e.AppendUint(42) }, uint(42)},
+		{"AppendUint64", func(e ArrayEncoder) { e.AppendUint64(42) }, uint64(42)},
+		{"AppendUint32", func(e ArrayEncoder) { e.AppendUint32(42) }, uint32(42)},
+		{"AppendUint16", func(e ArrayEncoder) { e.AppendUint16(42) }, uint16(42)},
+		{"AppendUint8", func(e ArrayEncoder) { e.AppendUint8(42) }, uint8(42)},
+		{"AppendUintptr", func(e ArrayEncoder) { e.AppendUintptr(42) }, uintptr(42)},
+		{
+			desc:     "AppendReflected",
+			f:        func(e ArrayEncoder) { e.AppendReflected(map[string]interface{}{"foo": 5}) },
+			expected: map[string]interface{}{"foo": 5},
+		},
+		{
+			desc: "AppendArray (arrays of arrays)",
+			f: func(e ArrayEncoder) {
+				e.AppendArray(ArrayMarshalerFunc(func(inner ArrayEncoder) error {
+					inner.AppendBool(true)
+					inner.AppendBool(false)
+					return nil
+				}))
+			},
+			expected: []interface{}{true, false},
+		},
+	}
+
+	for _, tt := range tests {
+		enc := NewMapObjectEncoder()
+		assert.NoError(t, enc.AddArray("k", ArrayMarshalerFunc(func(arr ArrayEncoder) error {
+			tt.f(arr)
+			tt.f(arr)
+			return nil
+		})), "Expected AddArray to succeed.")
+
+		arr, ok := enc.Fields["k"].([]interface{})
+		if !ok {
+			t.Errorf("Test case %s didn't encode an array.", tt.desc)
+			continue
+		}
+		assert.Equal(t, []interface{}{tt.expected, tt.expected}, arr, "Unexpected encoder output.")
+	}
+}
+
+func TestMapObjectEncoderReflectionFailures(t *testing.T) {
+	enc := NewMapObjectEncoder()
+	assert.Error(t, enc.AddObject("object", loggable{false}), "Expected AddObject to fail.")
+	assert.Equal(
+		t,
+		map[string]interface{}{"object": map[string]interface{}{}},
+		enc.Fields,
+		"Expected encoder to use empty values on errors.",
+	)
+}
diff --git a/vendor/go.uber.org/zap/zapcore/sampler.go b/vendor/go.uber.org/zap/zapcore/sampler.go
new file mode 100644
index 0000000..e316418
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/sampler.go
@@ -0,0 +1,134 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"time"
+
+	"go.uber.org/atomic"
+)
+
+const (
+	_numLevels        = _maxLevel - _minLevel + 1
+	_countersPerLevel = 4096
+)
+
+type counter struct {
+	resetAt atomic.Int64
+	counter atomic.Uint64
+}
+
+type counters [_numLevels][_countersPerLevel]counter
+
+func newCounters() *counters {
+	return &counters{}
+}
+
+func (cs *counters) get(lvl Level, key string) *counter {
+	i := lvl - _minLevel
+	j := fnv32a(key) % _countersPerLevel
+	return &cs[i][j]
+}
+
+// fnv32a, adapted from "hash/fnv", but without a []byte(string) alloc
+func fnv32a(s string) uint32 {
+	const (
+		offset32 = 2166136261
+		prime32  = 16777619
+	)
+	hash := uint32(offset32)
+	for i := 0; i < len(s); i++ {
+		hash ^= uint32(s[i])
+		hash *= prime32
+	}
+	return hash
+}
+
+func (c *counter) IncCheckReset(t time.Time, tick time.Duration) uint64 {
+	tn := t.UnixNano()
+	resetAfter := c.resetAt.Load()
+	if resetAfter > tn {
+		return c.counter.Inc()
+	}
+
+	c.counter.Store(1)
+
+	newResetAfter := tn + tick.Nanoseconds()
+	if !c.resetAt.CAS(resetAfter, newResetAfter) {
+		// We raced with another goroutine trying to reset, and it also reset
+		// the counter to 1, so we need to reincrement the counter.
+		return c.counter.Inc()
+	}
+
+	return 1
+}
+
+type sampler struct {
+	Core
+
+	counts            *counters
+	tick              time.Duration
+	first, thereafter uint64
+}
+
+// NewSampler creates a Core that samples incoming entries, which caps the CPU
+// and I/O load of logging while attempting to preserve a representative subset
+// of your logs.
+//
+// Zap samples by logging the first N entries with a given level and message
+// each tick. If more Entries with the same level and message are seen during
+// the same interval, every Mth message is logged and the rest are dropped.
+//
+// Keep in mind that zap's sampling implementation is optimized for speed over
+// absolute precision; under load, each tick may be slightly over- or
+// under-sampled.
+func NewSampler(core Core, tick time.Duration, first, thereafter int) Core {
+	return &sampler{
+		Core:       core,
+		tick:       tick,
+		counts:     newCounters(),
+		first:      uint64(first),
+		thereafter: uint64(thereafter),
+	}
+}
+
+func (s *sampler) With(fields []Field) Core {
+	return &sampler{
+		Core:       s.Core.With(fields),
+		tick:       s.tick,
+		counts:     s.counts,
+		first:      s.first,
+		thereafter: s.thereafter,
+	}
+}
+
+func (s *sampler) Check(ent Entry, ce *CheckedEntry) *CheckedEntry {
+	if !s.Enabled(ent.Level) {
+		return ce
+	}
+
+	counter := s.counts.get(ent.Level, ent.Message)
+	n := counter.IncCheckReset(ent.Time, s.tick)
+	if n > s.first && (n-s.first)%s.thereafter != 0 {
+		return ce
+	}
+	return s.Core.Check(ent, ce)
+}
diff --git a/vendor/go.uber.org/zap/zapcore/sampler_bench_test.go b/vendor/go.uber.org/zap/zapcore/sampler_bench_test.go
new file mode 100644
index 0000000..3c79932
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/sampler_bench_test.go
@@ -0,0 +1,230 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore_test
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	. "go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest"
+)
+
+var counterTestCases = [][]string{
+	// some stuff I made up
+	{
+		"foo",
+		"bar",
+		"baz",
+		"alpha",
+		"bravo",
+		"charlie",
+		"delta",
+	},
+
+	// shuf -n50 /usr/share/dict/words
+	{
+		"unbracing",
+		"stereotomy",
+		"supranervian",
+		"moaning",
+		"exchangeability",
+		"gunyang",
+		"sulcation",
+		"dariole",
+		"archheresy",
+		"synchronistically",
+		"clips",
+		"unsanctioned",
+		"Argoan",
+		"liparomphalus",
+		"layship",
+		"Fregatae",
+		"microzoology",
+		"glaciaria",
+		"Frugivora",
+		"patterist",
+		"Grossulariaceae",
+		"lithotint",
+		"bargander",
+		"opisthographical",
+		"cacography",
+		"chalkstone",
+		"nonsubstantialism",
+		"sardonicism",
+		"calamiform",
+		"lodginghouse",
+		"predisposedly",
+		"topotypic",
+		"broideress",
+		"outrange",
+		"gingivolabial",
+		"monoazo",
+		"sparlike",
+		"concameration",
+		"untoothed",
+		"Camorrism",
+		"reissuer",
+		"soap",
+		"palaiotype",
+		"countercharm",
+		"yellowbird",
+		"palterly",
+		"writinger",
+		"boatfalls",
+		"tuglike",
+		"underbitten",
+	},
+
+	// shuf -n100 /usr/share/dict/words
+	{
+		"rooty",
+		"malcultivation",
+		"degrade",
+		"pseudoindependent",
+		"stillatory",
+		"antiseptize",
+		"protoamphibian",
+		"antiar",
+		"Esther",
+		"pseudelminth",
+		"superfluitance",
+		"teallite",
+		"disunity",
+		"spirignathous",
+		"vergency",
+		"myliobatid",
+		"inosic",
+		"overabstemious",
+		"patriarchally",
+		"foreimagine",
+		"coetaneity",
+		"hemimellitene",
+		"hyperspatial",
+		"aulophyte",
+		"electropoion",
+		"antitrope",
+		"Amarantus",
+		"smaltine",
+		"lighthead",
+		"syntonically",
+		"incubous",
+		"versation",
+		"cirsophthalmia",
+		"Ulidian",
+		"homoeography",
+		"Velella",
+		"Hecatean",
+		"serfage",
+		"Spermaphyta",
+		"palatoplasty",
+		"electroextraction",
+		"aconite",
+		"avirulence",
+		"initiator",
+		"besmear",
+		"unrecognizably",
+		"euphoniousness",
+		"balbuties",
+		"pascuage",
+		"quebracho",
+		"Yakala",
+		"auriform",
+		"sevenbark",
+		"superorganism",
+		"telesterion",
+		"ensand",
+		"nagaika",
+		"anisuria",
+		"etching",
+		"soundingly",
+		"grumpish",
+		"drillmaster",
+		"perfumed",
+		"dealkylate",
+		"anthracitiferous",
+		"predefiance",
+		"sulphoxylate",
+		"freeness",
+		"untucking",
+		"misworshiper",
+		"Nestorianize",
+		"nonegoistical",
+		"construe",
+		"upstroke",
+		"teated",
+		"nasolachrymal",
+		"Mastodontidae",
+		"gallows",
+		"radioluminescent",
+		"uncourtierlike",
+		"phasmatrope",
+		"Clunisian",
+		"drainage",
+		"sootless",
+		"brachyfacial",
+		"antiheroism",
+		"irreligionize",
+		"ked",
+		"unfact",
+		"nonprofessed",
+		"milady",
+		"conjecture",
+		"Arctomys",
+		"guapilla",
+		"Sassenach",
+		"emmetrope",
+		"rosewort",
+		"raphidiferous",
+		"pooh",
+		"Tyndallize",
+	},
+}
+
+func BenchmarkSampler_Check(b *testing.B) {
+	for _, keys := range counterTestCases {
+		b.Run(fmt.Sprintf("%v keys", len(keys)), func(b *testing.B) {
+			fac := NewSampler(
+				NewCore(
+					NewJSONEncoder(testEncoderConfig()),
+					&zaptest.Discarder{},
+					DebugLevel,
+				),
+				time.Millisecond, 1, 1000)
+			b.ResetTimer()
+			b.RunParallel(func(pb *testing.PB) {
+				i := 0
+				for pb.Next() {
+					ent := Entry{
+						Level:   DebugLevel + Level(i%4),
+						Message: keys[i],
+					}
+					_ = fac.Check(ent, nil)
+					i++
+					if n := len(keys); i >= n {
+						i -= n
+					}
+				}
+			})
+		})
+	}
+}
diff --git a/vendor/go.uber.org/zap/zapcore/sampler_test.go b/vendor/go.uber.org/zap/zapcore/sampler_test.go
new file mode 100644
index 0000000..82588c9
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/sampler_test.go
@@ -0,0 +1,225 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore_test
+
+import (
+	"fmt"
+	"sync"
+	"testing"
+	"time"
+
+	"go.uber.org/atomic"
+	. "go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest"
+	"go.uber.org/zap/zaptest/observer"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func fakeSampler(lvl LevelEnabler, tick time.Duration, first, thereafter int) (Core, *observer.ObservedLogs) {
+	core, logs := observer.New(lvl)
+	core = NewSampler(core, tick, first, thereafter)
+	return core, logs
+}
+
+func assertSequence(t testing.TB, logs []observer.LoggedEntry, lvl Level, seq ...int64) {
+	seen := make([]int64, len(logs))
+	for i, entry := range logs {
+		require.Equal(t, "", entry.Message, "Message wasn't created by writeSequence.")
+		require.Equal(t, 1, len(entry.Context), "Unexpected number of fields.")
+		require.Equal(t, lvl, entry.Level, "Unexpected level.")
+		f := entry.Context[0]
+		require.Equal(t, "iter", f.Key, "Unexpected field key.")
+		require.Equal(t, Int64Type, f.Type, "Unexpected field type")
+		seen[i] = f.Integer
+	}
+	assert.Equal(t, seq, seen, "Unexpected sequence logged at level %v.", lvl)
+}
+
+func writeSequence(core Core, n int, lvl Level) {
+	// All tests using writeSequence verify that counters are shared between
+	// parent and child cores.
+	core = core.With([]Field{makeInt64Field("iter", n)})
+	if ce := core.Check(Entry{Level: lvl, Time: time.Now()}, nil); ce != nil {
+		ce.Write()
+	}
+}
+
+func TestSampler(t *testing.T) {
+	for _, lvl := range []Level{DebugLevel, InfoLevel, WarnLevel, ErrorLevel, DPanicLevel, PanicLevel, FatalLevel} {
+		sampler, logs := fakeSampler(DebugLevel, time.Minute, 2, 3)
+
+		// Ensure that counts aren't shared between levels.
+		probeLevel := DebugLevel
+		if lvl == DebugLevel {
+			probeLevel = InfoLevel
+		}
+		for i := 0; i < 10; i++ {
+			writeSequence(sampler, 1, probeLevel)
+		}
+		// Clear any output.
+		logs.TakeAll()
+
+		for i := 1; i < 10; i++ {
+			writeSequence(sampler, i, lvl)
+		}
+		assertSequence(t, logs.TakeAll(), lvl, 1, 2, 5, 8)
+	}
+}
+
+func TestSamplerDisabledLevels(t *testing.T) {
+	sampler, logs := fakeSampler(InfoLevel, time.Minute, 1, 100)
+
+	// Shouldn't be counted, because debug logging isn't enabled.
+	writeSequence(sampler, 1, DebugLevel)
+	writeSequence(sampler, 2, InfoLevel)
+	assertSequence(t, logs.TakeAll(), InfoLevel, 2)
+}
+
+func TestSamplerTicking(t *testing.T) {
+	// Ensure that we're resetting the sampler's counter every tick.
+	sampler, logs := fakeSampler(DebugLevel, 10*time.Millisecond, 5, 10)
+
+	// If we log five or fewer messages every tick, none of them should be
+	// dropped.
+	for tick := 0; tick < 2; tick++ {
+		for i := 1; i <= 5; i++ {
+			writeSequence(sampler, i, InfoLevel)
+		}
+		zaptest.Sleep(15 * time.Millisecond)
+	}
+	assertSequence(
+		t,
+		logs.TakeAll(),
+		InfoLevel,
+		1, 2, 3, 4, 5, // first tick
+		1, 2, 3, 4, 5, // second tick
+	)
+
+	// If we log quickly, we should drop some logs. The first five statements
+	// each tick should be logged, then every tenth.
+	for tick := 0; tick < 3; tick++ {
+		for i := 1; i < 18; i++ {
+			writeSequence(sampler, i, InfoLevel)
+		}
+		zaptest.Sleep(10 * time.Millisecond)
+	}
+
+	assertSequence(
+		t,
+		logs.TakeAll(),
+		InfoLevel,
+		1, 2, 3, 4, 5, 15, // first tick
+		1, 2, 3, 4, 5, 15, // second tick
+		1, 2, 3, 4, 5, 15, // third tick
+	)
+}
+
+type countingCore struct {
+	logs atomic.Uint32
+}
+
+func (c *countingCore) Check(ent Entry, ce *CheckedEntry) *CheckedEntry {
+	return ce.AddCore(ent, c)
+}
+
+func (c *countingCore) Write(Entry, []Field) error {
+	c.logs.Inc()
+	return nil
+}
+
+func (c *countingCore) With([]Field) Core { return c }
+func (*countingCore) Enabled(Level) bool  { return true }
+func (*countingCore) Sync() error         { return nil }
+
+func TestSamplerConcurrent(t *testing.T) {
+	const (
+		logsPerTick   = 10
+		numMessages   = 5
+		numTicks      = 25
+		numGoroutines = 10
+		expectedCount = numMessages * logsPerTick * numTicks
+	)
+
+	tick := zaptest.Timeout(10 * time.Millisecond)
+	cc := &countingCore{}
+	sampler := NewSampler(cc, tick, logsPerTick, 100000)
+
+	var (
+		done atomic.Bool
+		wg   sync.WaitGroup
+	)
+	for i := 0; i < numGoroutines; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+
+			for {
+				if done.Load() {
+					return
+				}
+				msg := fmt.Sprintf("msg%v", i%numMessages)
+				ent := Entry{Level: DebugLevel, Message: msg, Time: time.Now()}
+				if ce := sampler.Check(ent, nil); ce != nil {
+					ce.Write()
+				}
+
+				// Give a chance for other goroutines to run.
+				time.Sleep(time.Microsecond)
+			}
+		}(i)
+	}
+
+	time.AfterFunc(numTicks*tick, func() {
+		done.Store(true)
+	})
+	wg.Wait()
+
+	assert.InDelta(
+		t,
+		expectedCount,
+		cc.logs.Load(),
+		expectedCount/10,
+		"Unexpected number of logs",
+	)
+}
+
+func TestSamplerRaces(t *testing.T) {
+	sampler, _ := fakeSampler(DebugLevel, time.Minute, 1, 1000)
+
+	var wg sync.WaitGroup
+	start := make(chan struct{})
+
+	for i := 0; i < 100; i++ {
+		wg.Add(1)
+		go func() {
+			<-start
+			for j := 0; j < 100; j++ {
+				writeSequence(sampler, j, InfoLevel)
+			}
+			wg.Done()
+		}()
+	}
+
+	close(start)
+	wg.Wait()
+}
diff --git a/vendor/go.uber.org/zap/zapcore/tee.go b/vendor/go.uber.org/zap/zapcore/tee.go
new file mode 100644
index 0000000..07a32ee
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/tee.go
@@ -0,0 +1,81 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import "go.uber.org/multierr"
+
+type multiCore []Core
+
+// NewTee creates a Core that duplicates log entries into two or more
+// underlying Cores.
+//
+// Calling it with a single Core returns the input unchanged, and calling
+// it with no input returns a no-op Core.
+func NewTee(cores ...Core) Core {
+	switch len(cores) {
+	case 0:
+		return NewNopCore()
+	case 1:
+		return cores[0]
+	default:
+		return multiCore(cores)
+	}
+}
+
+func (mc multiCore) With(fields []Field) Core {
+	clone := make(multiCore, len(mc))
+	for i := range mc {
+		clone[i] = mc[i].With(fields)
+	}
+	return clone
+}
+
+func (mc multiCore) Enabled(lvl Level) bool {
+	for i := range mc {
+		if mc[i].Enabled(lvl) {
+			return true
+		}
+	}
+	return false
+}
+
+func (mc multiCore) Check(ent Entry, ce *CheckedEntry) *CheckedEntry {
+	for i := range mc {
+		ce = mc[i].Check(ent, ce)
+	}
+	return ce
+}
+
+func (mc multiCore) Write(ent Entry, fields []Field) error {
+	var err error
+	for i := range mc {
+		err = multierr.Append(err, mc[i].Write(ent, fields))
+	}
+	return err
+}
+
+func (mc multiCore) Sync() error {
+	var err error
+	for i := range mc {
+		err = multierr.Append(err, mc[i].Sync())
+	}
+	return err
+}
diff --git a/vendor/go.uber.org/zap/zapcore/tee_logger_bench_test.go b/vendor/go.uber.org/zap/zapcore/tee_logger_bench_test.go
new file mode 100644
index 0000000..041f10a
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/tee_logger_bench_test.go
@@ -0,0 +1,62 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore_test
+
+import (
+	"testing"
+
+	. "go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest"
+)
+
+func withBenchedTee(b *testing.B, f func(Core)) {
+	fac := NewTee(
+		NewCore(NewJSONEncoder(testEncoderConfig()), &zaptest.Discarder{}, DebugLevel),
+		NewCore(NewJSONEncoder(testEncoderConfig()), &zaptest.Discarder{}, InfoLevel),
+	)
+	b.ResetTimer()
+	f(fac)
+}
+
+func BenchmarkTeeCheck(b *testing.B) {
+	cases := []struct {
+		lvl Level
+		msg string
+	}{
+		{DebugLevel, "foo"},
+		{InfoLevel, "bar"},
+		{WarnLevel, "baz"},
+		{ErrorLevel, "babble"},
+	}
+	withBenchedTee(b, func(core Core) {
+		b.RunParallel(func(pb *testing.PB) {
+			i := 0
+			for pb.Next() {
+				tt := cases[i]
+				entry := Entry{Level: tt.lvl, Message: tt.msg}
+				if cm := core.Check(entry, nil); cm != nil {
+					cm.Write(Field{Key: "i", Integer: int64(i), Type: Int64Type})
+				}
+				i = (i + 1) % len(cases)
+			}
+		})
+	})
+}
diff --git a/vendor/go.uber.org/zap/zapcore/tee_test.go b/vendor/go.uber.org/zap/zapcore/tee_test.go
new file mode 100644
index 0000000..754abbb
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/tee_test.go
@@ -0,0 +1,153 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore_test
+
+import (
+	"errors"
+	"testing"
+
+	. "go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest"
+	"go.uber.org/zap/zaptest/observer"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func withTee(f func(core Core, debugLogs, warnLogs *observer.ObservedLogs)) {
+	debugLogger, debugLogs := observer.New(DebugLevel)
+	warnLogger, warnLogs := observer.New(WarnLevel)
+	tee := NewTee(debugLogger, warnLogger)
+	f(tee, debugLogs, warnLogs)
+}
+
+func TestTeeUnusualInput(t *testing.T) {
+	// Verify that Tee handles receiving one and no inputs correctly.
+	t.Run("one input", func(t *testing.T) {
+		obs, _ := observer.New(DebugLevel)
+		assert.Equal(t, obs, NewTee(obs), "Expected to return single inputs unchanged.")
+	})
+	t.Run("no input", func(t *testing.T) {
+		assert.Equal(t, NewNopCore(), NewTee(), "Expected to return NopCore.")
+	})
+}
+
+func TestTeeCheck(t *testing.T) {
+	withTee(func(tee Core, debugLogs, warnLogs *observer.ObservedLogs) {
+		debugEntry := Entry{Level: DebugLevel, Message: "log-at-debug"}
+		infoEntry := Entry{Level: InfoLevel, Message: "log-at-info"}
+		warnEntry := Entry{Level: WarnLevel, Message: "log-at-warn"}
+		errorEntry := Entry{Level: ErrorLevel, Message: "log-at-error"}
+		for _, ent := range []Entry{debugEntry, infoEntry, warnEntry, errorEntry} {
+			if ce := tee.Check(ent, nil); ce != nil {
+				ce.Write()
+			}
+		}
+
+		assert.Equal(t, []observer.LoggedEntry{
+			{Entry: debugEntry, Context: []Field{}},
+			{Entry: infoEntry, Context: []Field{}},
+			{Entry: warnEntry, Context: []Field{}},
+			{Entry: errorEntry, Context: []Field{}},
+		}, debugLogs.All())
+
+		assert.Equal(t, []observer.LoggedEntry{
+			{Entry: warnEntry, Context: []Field{}},
+			{Entry: errorEntry, Context: []Field{}},
+		}, warnLogs.All())
+	})
+}
+
+func TestTeeWrite(t *testing.T) {
+	// Calling the tee's Write method directly should always log, regardless of
+	// the configured level.
+	withTee(func(tee Core, debugLogs, warnLogs *observer.ObservedLogs) {
+		debugEntry := Entry{Level: DebugLevel, Message: "log-at-debug"}
+		warnEntry := Entry{Level: WarnLevel, Message: "log-at-warn"}
+		for _, ent := range []Entry{debugEntry, warnEntry} {
+			tee.Write(ent, nil)
+		}
+
+		for _, logs := range []*observer.ObservedLogs{debugLogs, warnLogs} {
+			assert.Equal(t, []observer.LoggedEntry{
+				{Entry: debugEntry, Context: []Field{}},
+				{Entry: warnEntry, Context: []Field{}},
+			}, logs.All())
+		}
+	})
+}
+
+func TestTeeWith(t *testing.T) {
+	withTee(func(tee Core, debugLogs, warnLogs *observer.ObservedLogs) {
+		f := makeInt64Field("k", 42)
+		tee = tee.With([]Field{f})
+		ent := Entry{Level: WarnLevel, Message: "log-at-warn"}
+		if ce := tee.Check(ent, nil); ce != nil {
+			ce.Write()
+		}
+
+		for _, logs := range []*observer.ObservedLogs{debugLogs, warnLogs} {
+			assert.Equal(t, []observer.LoggedEntry{
+				{Entry: ent, Context: []Field{f}},
+			}, logs.All())
+		}
+	})
+}
+
+func TestTeeEnabled(t *testing.T) {
+	infoLogger, _ := observer.New(InfoLevel)
+	warnLogger, _ := observer.New(WarnLevel)
+	tee := NewTee(infoLogger, warnLogger)
+	tests := []struct {
+		lvl     Level
+		enabled bool
+	}{
+		{DebugLevel, false},
+		{InfoLevel, true},
+		{WarnLevel, true},
+		{ErrorLevel, true},
+		{DPanicLevel, true},
+		{PanicLevel, true},
+		{FatalLevel, true},
+	}
+
+	for _, tt := range tests {
+		assert.Equal(t, tt.enabled, tee.Enabled(tt.lvl), "Unexpected Enabled result for level %s.", tt.lvl)
+	}
+}
+
+func TestTeeSync(t *testing.T) {
+	infoLogger, _ := observer.New(InfoLevel)
+	warnLogger, _ := observer.New(WarnLevel)
+	tee := NewTee(infoLogger, warnLogger)
+	assert.NoError(t, tee.Sync(), "Unexpected error from Syncing a tee.")
+
+	sink := &zaptest.Discarder{}
+	err := errors.New("failed")
+	sink.SetError(err)
+
+	noSync := NewCore(
+		NewJSONEncoder(testEncoderConfig()),
+		sink,
+		DebugLevel,
+	)
+	tee = NewTee(tee, noSync)
+	assert.Equal(t, err, tee.Sync(), "Expected an error when part of tee can't Sync.")
+}
diff --git a/vendor/go.uber.org/zap/zapcore/write_syncer.go b/vendor/go.uber.org/zap/zapcore/write_syncer.go
new file mode 100644
index 0000000..209e25f
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/write_syncer.go
@@ -0,0 +1,123 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"io"
+	"sync"
+
+	"go.uber.org/multierr"
+)
+
+// A WriteSyncer is an io.Writer that can also flush any buffered data. Note
+// that *os.File (and thus, os.Stderr and os.Stdout) implement WriteSyncer.
+type WriteSyncer interface {
+	io.Writer
+	Sync() error
+}
+
+// AddSync converts an io.Writer to a WriteSyncer. It attempts to be
+// intelligent: if the concrete type of the io.Writer implements WriteSyncer,
+// we'll use the existing Sync method. If it doesn't, we'll add a no-op Sync.
+func AddSync(w io.Writer) WriteSyncer {
+	switch w := w.(type) {
+	case WriteSyncer:
+		return w
+	default:
+		return writerWrapper{w}
+	}
+}
+
+type lockedWriteSyncer struct {
+	sync.Mutex
+	ws WriteSyncer
+}
+
+// Lock wraps a WriteSyncer in a mutex to make it safe for concurrent use. In
+// particular, *os.Files must be locked before use.
+func Lock(ws WriteSyncer) WriteSyncer {
+	if _, ok := ws.(*lockedWriteSyncer); ok {
+		// no need to layer on another lock
+		return ws
+	}
+	return &lockedWriteSyncer{ws: ws}
+}
+
+func (s *lockedWriteSyncer) Write(bs []byte) (int, error) {
+	s.Lock()
+	n, err := s.ws.Write(bs)
+	s.Unlock()
+	return n, err
+}
+
+func (s *lockedWriteSyncer) Sync() error {
+	s.Lock()
+	err := s.ws.Sync()
+	s.Unlock()
+	return err
+}
+
+type writerWrapper struct {
+	io.Writer
+}
+
+func (w writerWrapper) Sync() error {
+	return nil
+}
+
+type multiWriteSyncer []WriteSyncer
+
+// NewMultiWriteSyncer creates a WriteSyncer that duplicates its writes
+// and sync calls, much like io.MultiWriter.
+func NewMultiWriteSyncer(ws ...WriteSyncer) WriteSyncer {
+	if len(ws) == 1 {
+		return ws[0]
+	}
+	// Copy to protect against https://github.com/golang/go/issues/7809
+	return multiWriteSyncer(append([]WriteSyncer(nil), ws...))
+}
+
+// See https://golang.org/src/io/multi.go
+// When not all underlying syncers write the same number of bytes,
+// the smallest number is returned even though Write() is called on
+// all of them.
+func (ws multiWriteSyncer) Write(p []byte) (int, error) {
+	var writeErr error
+	nWritten := 0
+	for _, w := range ws {
+		n, err := w.Write(p)
+		writeErr = multierr.Append(writeErr, err)
+		if nWritten == 0 && n != 0 {
+			nWritten = n
+		} else if n < nWritten {
+			nWritten = n
+		}
+	}
+	return nWritten, writeErr
+}
+
+func (ws multiWriteSyncer) Sync() error {
+	var err error
+	for _, w := range ws {
+		err = multierr.Append(err, w.Sync())
+	}
+	return err
+}
diff --git a/vendor/go.uber.org/zap/zapcore/write_syncer_bench_test.go b/vendor/go.uber.org/zap/zapcore/write_syncer_bench_test.go
new file mode 100644
index 0000000..0adcad8
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/write_syncer_bench_test.go
@@ -0,0 +1,56 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"testing"
+
+	"go.uber.org/zap/zaptest"
+)
+
+func BenchmarkMultiWriteSyncer(b *testing.B) {
+	b.Run("2", func(b *testing.B) {
+		w := NewMultiWriteSyncer(
+			&zaptest.Discarder{},
+			&zaptest.Discarder{},
+		)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				w.Write([]byte("foobarbazbabble"))
+			}
+		})
+	})
+	b.Run("4", func(b *testing.B) {
+		w := NewMultiWriteSyncer(
+			&zaptest.Discarder{},
+			&zaptest.Discarder{},
+			&zaptest.Discarder{},
+			&zaptest.Discarder{},
+		)
+		b.ResetTimer()
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				w.Write([]byte("foobarbazbabble"))
+			}
+		})
+	})
+}
diff --git a/vendor/go.uber.org/zap/zapcore/write_syncer_test.go b/vendor/go.uber.org/zap/zapcore/write_syncer_test.go
new file mode 100644
index 0000000..084b94a
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapcore/write_syncer_test.go
@@ -0,0 +1,137 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapcore
+
+import (
+	"bytes"
+	"errors"
+	"testing"
+
+	"io"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/zap/zaptest"
+)
+
+type writeSyncSpy struct {
+	io.Writer
+	zaptest.Syncer
+}
+
+func requireWriteWorks(t testing.TB, ws WriteSyncer) {
+	n, err := ws.Write([]byte("foo"))
+	require.NoError(t, err, "Unexpected error writing to WriteSyncer.")
+	require.Equal(t, 3, n, "Wrote an unexpected number of bytes.")
+}
+
+func TestAddSyncWriteSyncer(t *testing.T) {
+	buf := &bytes.Buffer{}
+	concrete := &writeSyncSpy{Writer: buf}
+	ws := AddSync(concrete)
+	requireWriteWorks(t, ws)
+
+	require.NoError(t, ws.Sync(), "Unexpected error syncing a WriteSyncer.")
+	require.True(t, concrete.Called(), "Expected to dispatch to concrete type's Sync method.")
+
+	concrete.SetError(errors.New("fail"))
+	assert.Error(t, ws.Sync(), "Expected to propagate errors from concrete type's Sync method.")
+}
+
+func TestAddSyncWriter(t *testing.T) {
+	// If we pass a plain io.Writer, make sure that we still get a WriteSyncer
+	// with a no-op Sync.
+	buf := &bytes.Buffer{}
+	ws := AddSync(buf)
+	requireWriteWorks(t, ws)
+	assert.NoError(t, ws.Sync(), "Unexpected error calling a no-op Sync method.")
+}
+
+func TestNewMultiWriteSyncerWorksForSingleWriter(t *testing.T) {
+	w := &zaptest.Buffer{}
+
+	ws := NewMultiWriteSyncer(w)
+	assert.Equal(t, w, ws, "Expected NewMultiWriteSyncer to return the same WriteSyncer object for a single argument.")
+
+	ws.Sync()
+	assert.True(t, w.Called(), "Expected Sync to be called on the created WriteSyncer")
+}
+
+func TestMultiWriteSyncerWritesBoth(t *testing.T) {
+	first := &bytes.Buffer{}
+	second := &bytes.Buffer{}
+	ws := NewMultiWriteSyncer(AddSync(first), AddSync(second))
+
+	msg := []byte("dumbledore")
+	n, err := ws.Write(msg)
+	require.NoError(t, err, "Expected successful buffer write")
+	assert.Equal(t, len(msg), n)
+
+	assert.Equal(t, msg, first.Bytes())
+	assert.Equal(t, msg, second.Bytes())
+}
+
+func TestMultiWriteSyncerFailsWrite(t *testing.T) {
+	ws := NewMultiWriteSyncer(AddSync(&zaptest.FailWriter{}))
+	_, err := ws.Write([]byte("test"))
+	assert.Error(t, err, "Write error should propagate")
+}
+
+func TestMultiWriteSyncerFailsShortWrite(t *testing.T) {
+	ws := NewMultiWriteSyncer(AddSync(&zaptest.ShortWriter{}))
+	n, err := ws.Write([]byte("test"))
+	assert.NoError(t, err, "Expected fake-success from short write")
+	assert.Equal(t, 3, n, "Expected byte count to return from underlying writer")
+}
+
+func TestWritestoAllSyncs_EvenIfFirstErrors(t *testing.T) {
+	failer := &zaptest.FailWriter{}
+	second := &bytes.Buffer{}
+	ws := NewMultiWriteSyncer(AddSync(failer), AddSync(second))
+
+	_, err := ws.Write([]byte("fail"))
+	assert.Error(t, err, "Expected error from call to a writer that failed")
+	assert.Equal(t, []byte("fail"), second.Bytes(), "Expected second sink to be written after first error")
+}
+
+func TestMultiWriteSyncerSync_PropagatesErrors(t *testing.T) {
+	badsink := &zaptest.Buffer{}
+	badsink.SetError(errors.New("sink is full"))
+	ws := NewMultiWriteSyncer(&zaptest.Discarder{}, badsink)
+
+	assert.Error(t, ws.Sync(), "Expected sync error to propagate")
+}
+
+func TestMultiWriteSyncerSync_NoErrorsOnDiscard(t *testing.T) {
+	ws := NewMultiWriteSyncer(&zaptest.Discarder{})
+	assert.NoError(t, ws.Sync(), "Expected error-free sync to /dev/null")
+}
+
+func TestMultiWriteSyncerSync_AllCalled(t *testing.T) {
+	failed, second := &zaptest.Buffer{}, &zaptest.Buffer{}
+
+	failed.SetError(errors.New("disposal broken"))
+	ws := NewMultiWriteSyncer(failed, second)
+
+	assert.Error(t, ws.Sync(), "Expected first sink to fail")
+	assert.True(t, failed.Called(), "Expected first sink to have Sync method called.")
+	assert.True(t, second.Called(), "Expected call to Sync even with first failure.")
+}
diff --git a/vendor/go.uber.org/zap/zapgrpc/zapgrpc.go b/vendor/go.uber.org/zap/zapgrpc/zapgrpc.go
new file mode 100644
index 0000000..1181e6a
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapgrpc/zapgrpc.go
@@ -0,0 +1,100 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Package zapgrpc provides a logger that is compatible with grpclog.
+package zapgrpc // import "go.uber.org/zap/zapgrpc"
+
+import "go.uber.org/zap"
+
+// An Option overrides a Logger's default configuration.
+type Option interface {
+	apply(*Logger)
+}
+
+type optionFunc func(*Logger)
+
+func (f optionFunc) apply(log *Logger) {
+	f(log)
+}
+
+// WithDebug configures a Logger to print at zap's DebugLevel instead of
+// InfoLevel.
+func WithDebug() Option {
+	return optionFunc(func(logger *Logger) {
+		logger.print = (*zap.SugaredLogger).Debug
+		logger.printf = (*zap.SugaredLogger).Debugf
+	})
+}
+
+// NewLogger returns a new Logger.
+//
+// By default, Loggers print at zap's InfoLevel.
+func NewLogger(l *zap.Logger, options ...Option) *Logger {
+	logger := &Logger{
+		log:    l.Sugar(),
+		fatal:  (*zap.SugaredLogger).Fatal,
+		fatalf: (*zap.SugaredLogger).Fatalf,
+		print:  (*zap.SugaredLogger).Info,
+		printf: (*zap.SugaredLogger).Infof,
+	}
+	for _, option := range options {
+		option.apply(logger)
+	}
+	return logger
+}
+
+// Logger adapts zap's Logger to be compatible with grpclog.Logger.
+type Logger struct {
+	log    *zap.SugaredLogger
+	fatal  func(*zap.SugaredLogger, ...interface{})
+	fatalf func(*zap.SugaredLogger, string, ...interface{})
+	print  func(*zap.SugaredLogger, ...interface{})
+	printf func(*zap.SugaredLogger, string, ...interface{})
+}
+
+// Fatal implements grpclog.Logger.
+func (l *Logger) Fatal(args ...interface{}) {
+	l.fatal(l.log, args...)
+}
+
+// Fatalf implements grpclog.Logger.
+func (l *Logger) Fatalf(format string, args ...interface{}) {
+	l.fatalf(l.log, format, args...)
+}
+
+// Fatalln implements grpclog.Logger.
+func (l *Logger) Fatalln(args ...interface{}) {
+	l.fatal(l.log, args...)
+}
+
+// Print implements grpclog.Logger.
+func (l *Logger) Print(args ...interface{}) {
+	l.print(l.log, args...)
+}
+
+// Printf implements grpclog.Logger.
+func (l *Logger) Printf(format string, args ...interface{}) {
+	l.printf(l.log, format, args...)
+}
+
+// Println implements grpclog.Logger.
+func (l *Logger) Println(args ...interface{}) {
+	l.print(l.log, args...)
+}
diff --git a/vendor/go.uber.org/zap/zapgrpc/zapgrpc_test.go b/vendor/go.uber.org/zap/zapgrpc/zapgrpc_test.go
new file mode 100644
index 0000000..036f3d7
--- /dev/null
+++ b/vendor/go.uber.org/zap/zapgrpc/zapgrpc_test.go
@@ -0,0 +1,115 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zapgrpc
+
+import (
+	"testing"
+
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest/observer"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestLoggerInfoExpected(t *testing.T) {
+	checkMessages(t, zapcore.DebugLevel, nil, zapcore.InfoLevel, []string{
+		"hello",
+		"world",
+		"foo",
+	}, func(logger *Logger) {
+		logger.Print("hello")
+		logger.Printf("world")
+		logger.Println("foo")
+	})
+}
+
+func TestLoggerDebugExpected(t *testing.T) {
+	checkMessages(t, zapcore.DebugLevel, []Option{WithDebug()}, zapcore.DebugLevel, []string{
+		"hello",
+		"world",
+		"foo",
+	}, func(logger *Logger) {
+		logger.Print("hello")
+		logger.Printf("world")
+		logger.Println("foo")
+	})
+}
+
+func TestLoggerDebugSuppressed(t *testing.T) {
+	checkMessages(t, zapcore.InfoLevel, []Option{WithDebug()}, zapcore.DebugLevel, nil, func(logger *Logger) {
+		logger.Print("hello")
+		logger.Printf("world")
+		logger.Println("foo")
+	})
+}
+
+func TestLoggerFatalExpected(t *testing.T) {
+	checkMessages(t, zapcore.DebugLevel, nil, zapcore.FatalLevel, []string{
+		"hello",
+		"world",
+		"foo",
+	}, func(logger *Logger) {
+		logger.Fatal("hello")
+		logger.Fatalf("world")
+		logger.Fatalln("foo")
+	})
+}
+
+func checkMessages(
+	t testing.TB,
+	enab zapcore.LevelEnabler,
+	opts []Option,
+	expectedLevel zapcore.Level,
+	expectedMessages []string,
+	f func(*Logger),
+) {
+	if expectedLevel == zapcore.FatalLevel {
+		expectedLevel = zapcore.WarnLevel
+	}
+	withLogger(enab, opts, func(logger *Logger, observedLogs *observer.ObservedLogs) {
+		f(logger)
+		logEntries := observedLogs.All()
+		require.Equal(t, len(expectedMessages), len(logEntries))
+		for i, logEntry := range logEntries {
+			require.Equal(t, expectedLevel, logEntry.Level)
+			require.Equal(t, expectedMessages[i], logEntry.Message)
+		}
+	})
+}
+
+func withLogger(
+	enab zapcore.LevelEnabler,
+	opts []Option,
+	f func(*Logger, *observer.ObservedLogs),
+) {
+	core, observedLogs := observer.New(enab)
+	f(NewLogger(zap.New(core), append(opts, withWarn())...), observedLogs)
+}
+
+// withWarn redirects the fatal level to the warn level, which makes testing
+// easier.
+func withWarn() Option {
+	return optionFunc(func(logger *Logger) {
+		logger.fatal = (*zap.SugaredLogger).Warn
+		logger.fatalf = (*zap.SugaredLogger).Warnf
+	})
+}
diff --git a/vendor/go.uber.org/zap/zaptest/doc.go b/vendor/go.uber.org/zap/zaptest/doc.go
new file mode 100644
index 0000000..464f589
--- /dev/null
+++ b/vendor/go.uber.org/zap/zaptest/doc.go
@@ -0,0 +1,27 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Package zaptest provides low-level helpers for testing log output. These
+// utilities are helpful in zap's own unit tests, but any assertions using
+// them are strongly coupled to a single encoding.
+//
+// Most users should use go.uber.org/zap/zaptest/observer instead of this
+// package.
+package zaptest // import "go.uber.org/zap/zaptest"
diff --git a/vendor/go.uber.org/zap/zaptest/observer/logged_entry.go b/vendor/go.uber.org/zap/zaptest/observer/logged_entry.go
new file mode 100644
index 0000000..a4ea7ec
--- /dev/null
+++ b/vendor/go.uber.org/zap/zaptest/observer/logged_entry.go
@@ -0,0 +1,39 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package observer
+
+import "go.uber.org/zap/zapcore"
+
+// An LoggedEntry is an encoding-agnostic representation of a log message.
+// Field availability is context dependant.
+type LoggedEntry struct {
+	zapcore.Entry
+	Context []zapcore.Field
+}
+
+// ContextMap returns a map for all fields in Context.
+func (e LoggedEntry) ContextMap() map[string]interface{} {
+	encoder := zapcore.NewMapObjectEncoder()
+	for _, f := range e.Context {
+		f.AddTo(encoder)
+	}
+	return encoder.Fields
+}
diff --git a/vendor/go.uber.org/zap/zaptest/observer/logged_entry_test.go b/vendor/go.uber.org/zap/zaptest/observer/logged_entry_test.go
new file mode 100644
index 0000000..50f6123
--- /dev/null
+++ b/vendor/go.uber.org/zap/zaptest/observer/logged_entry_test.go
@@ -0,0 +1,88 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package observer
+
+import (
+	"testing"
+
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestLoggedEntryContextMap(t *testing.T) {
+	tests := []struct {
+		msg    string
+		fields []zapcore.Field
+		want   map[string]interface{}
+	}{
+		{
+			msg:    "no fields",
+			fields: nil,
+			want:   map[string]interface{}{},
+		},
+		{
+			msg: "simple",
+			fields: []zapcore.Field{
+				zap.String("k1", "v"),
+				zap.Int64("k2", 10),
+			},
+			want: map[string]interface{}{
+				"k1": "v",
+				"k2": int64(10),
+			},
+		},
+		{
+			msg: "overwrite",
+			fields: []zapcore.Field{
+				zap.String("k1", "v1"),
+				zap.String("k1", "v2"),
+			},
+			want: map[string]interface{}{
+				"k1": "v2",
+			},
+		},
+		{
+			msg: "nested",
+			fields: []zapcore.Field{
+				zap.String("k1", "v1"),
+				zap.Namespace("nested"),
+				zap.String("k2", "v2"),
+			},
+			want: map[string]interface{}{
+				"k1": "v1",
+				"nested": map[string]interface{}{
+					"k2": "v2",
+				},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.msg, func(t *testing.T) {
+			entry := LoggedEntry{
+				Context: tt.fields,
+			}
+			assert.Equal(t, tt.want, entry.ContextMap())
+		})
+	}
+}
diff --git a/vendor/go.uber.org/zap/zaptest/observer/observer.go b/vendor/go.uber.org/zap/zaptest/observer/observer.go
new file mode 100644
index 0000000..78f5be4
--- /dev/null
+++ b/vendor/go.uber.org/zap/zaptest/observer/observer.go
@@ -0,0 +1,167 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Package observer provides a zapcore.Core that keeps an in-memory,
+// encoding-agnostic repesentation of log entries. It's useful for
+// applications that want to unit test their log output without tying their
+// tests to a particular output encoding.
+package observer // import "go.uber.org/zap/zaptest/observer"
+
+import (
+	"strings"
+	"sync"
+	"time"
+
+	"go.uber.org/zap/zapcore"
+)
+
+// ObservedLogs is a concurrency-safe, ordered collection of observed logs.
+type ObservedLogs struct {
+	mu   sync.RWMutex
+	logs []LoggedEntry
+}
+
+// Len returns the number of items in the collection.
+func (o *ObservedLogs) Len() int {
+	o.mu.RLock()
+	n := len(o.logs)
+	o.mu.RUnlock()
+	return n
+}
+
+// All returns a copy of all the observed logs.
+func (o *ObservedLogs) All() []LoggedEntry {
+	o.mu.RLock()
+	ret := make([]LoggedEntry, len(o.logs))
+	for i := range o.logs {
+		ret[i] = o.logs[i]
+	}
+	o.mu.RUnlock()
+	return ret
+}
+
+// TakeAll returns a copy of all the observed logs, and truncates the observed
+// slice.
+func (o *ObservedLogs) TakeAll() []LoggedEntry {
+	o.mu.Lock()
+	ret := o.logs
+	o.logs = nil
+	o.mu.Unlock()
+	return ret
+}
+
+// AllUntimed returns a copy of all the observed logs, but overwrites the
+// observed timestamps with time.Time's zero value. This is useful when making
+// assertions in tests.
+func (o *ObservedLogs) AllUntimed() []LoggedEntry {
+	ret := o.All()
+	for i := range ret {
+		ret[i].Time = time.Time{}
+	}
+	return ret
+}
+
+// FilterMessage filters entries to those that have the specified message.
+func (o *ObservedLogs) FilterMessage(msg string) *ObservedLogs {
+	return o.filter(func(e LoggedEntry) bool {
+		return e.Message == msg
+	})
+}
+
+// FilterMessageSnippet filters entries to those that have a message containing the specified snippet.
+func (o *ObservedLogs) FilterMessageSnippet(snippet string) *ObservedLogs {
+	return o.filter(func(e LoggedEntry) bool {
+		return strings.Contains(e.Message, snippet)
+	})
+}
+
+// FilterField filters entries to those that have the specified field.
+func (o *ObservedLogs) FilterField(field zapcore.Field) *ObservedLogs {
+	return o.filter(func(e LoggedEntry) bool {
+		for _, ctxField := range e.Context {
+			if ctxField.Equals(field) {
+				return true
+			}
+		}
+		return false
+	})
+}
+
+func (o *ObservedLogs) filter(match func(LoggedEntry) bool) *ObservedLogs {
+	o.mu.RLock()
+	defer o.mu.RUnlock()
+
+	var filtered []LoggedEntry
+	for _, entry := range o.logs {
+		if match(entry) {
+			filtered = append(filtered, entry)
+		}
+	}
+	return &ObservedLogs{logs: filtered}
+}
+
+func (o *ObservedLogs) add(log LoggedEntry) {
+	o.mu.Lock()
+	o.logs = append(o.logs, log)
+	o.mu.Unlock()
+}
+
+// New creates a new Core that buffers logs in memory (without any encoding).
+// It's particularly useful in tests.
+func New(enab zapcore.LevelEnabler) (zapcore.Core, *ObservedLogs) {
+	ol := &ObservedLogs{}
+	return &contextObserver{
+		LevelEnabler: enab,
+		logs:         ol,
+	}, ol
+}
+
+type contextObserver struct {
+	zapcore.LevelEnabler
+	logs    *ObservedLogs
+	context []zapcore.Field
+}
+
+func (co *contextObserver) Check(ent zapcore.Entry, ce *zapcore.CheckedEntry) *zapcore.CheckedEntry {
+	if co.Enabled(ent.Level) {
+		return ce.AddCore(ent, co)
+	}
+	return ce
+}
+
+func (co *contextObserver) With(fields []zapcore.Field) zapcore.Core {
+	return &contextObserver{
+		LevelEnabler: co.LevelEnabler,
+		logs:         co.logs,
+		context:      append(co.context[:len(co.context):len(co.context)], fields...),
+	}
+}
+
+func (co *contextObserver) Write(ent zapcore.Entry, fields []zapcore.Field) error {
+	all := make([]zapcore.Field, 0, len(fields)+len(co.context))
+	all = append(all, co.context...)
+	all = append(all, fields...)
+	co.logs.add(LoggedEntry{ent, all})
+	return nil
+}
+
+func (co *contextObserver) Sync() error {
+	return nil
+}
diff --git a/vendor/go.uber.org/zap/zaptest/observer/observer_test.go b/vendor/go.uber.org/zap/zaptest/observer/observer_test.go
new file mode 100644
index 0000000..e1a0da7
--- /dev/null
+++ b/vendor/go.uber.org/zap/zaptest/observer/observer_test.go
@@ -0,0 +1,215 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package observer_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+	. "go.uber.org/zap/zaptest/observer"
+)
+
+func assertEmpty(t testing.TB, logs *ObservedLogs) {
+	assert.Equal(t, 0, logs.Len(), "Expected empty ObservedLogs to have zero length.")
+	assert.Equal(t, []LoggedEntry{}, logs.All(), "Unexpected LoggedEntries in empty ObservedLogs.")
+}
+
+func TestObserver(t *testing.T) {
+	observer, logs := New(zap.InfoLevel)
+	assertEmpty(t, logs)
+
+	assert.NoError(t, observer.Sync(), "Unexpected failure in no-op Sync")
+
+	obs := zap.New(observer).With(zap.Int("i", 1))
+	obs.Info("foo")
+	obs.Debug("bar")
+	want := []LoggedEntry{{
+		Entry:   zapcore.Entry{Level: zap.InfoLevel, Message: "foo"},
+		Context: []zapcore.Field{zap.Int("i", 1)},
+	}}
+
+	assert.Equal(t, 1, logs.Len(), "Unexpected observed logs Len.")
+	assert.Equal(t, want, logs.AllUntimed(), "Unexpected contents from AllUntimed.")
+
+	all := logs.All()
+	require.Equal(t, 1, len(all), "Unexpected numbed of LoggedEntries returned from All.")
+	assert.NotEqual(t, time.Time{}, all[0].Time, "Expected non-zero time on LoggedEntry.")
+
+	// copy & zero time for stable assertions
+	untimed := append([]LoggedEntry{}, all...)
+	untimed[0].Time = time.Time{}
+	assert.Equal(t, want, untimed, "Unexpected LoggedEntries from All.")
+
+	assert.Equal(t, all, logs.TakeAll(), "Expected All and TakeAll to return identical results.")
+	assertEmpty(t, logs)
+}
+
+func TestObserverWith(t *testing.T) {
+	sf1, logs := New(zap.InfoLevel)
+
+	// need to pad out enough initial fields so that the underlying slice cap()
+	// gets ahead of its len() so that the sf3/4 With append's could choose
+	// not to copy (if the implementation doesn't force them)
+	sf1 = sf1.With([]zapcore.Field{zap.Int("a", 1), zap.Int("b", 2)})
+
+	sf2 := sf1.With([]zapcore.Field{zap.Int("c", 3)})
+	sf3 := sf2.With([]zapcore.Field{zap.Int("d", 4)})
+	sf4 := sf2.With([]zapcore.Field{zap.Int("e", 5)})
+	ent := zapcore.Entry{Level: zap.InfoLevel, Message: "hello"}
+
+	for i, core := range []zapcore.Core{sf2, sf3, sf4} {
+		if ce := core.Check(ent, nil); ce != nil {
+			ce.Write(zap.Int("i", i))
+		}
+	}
+
+	assert.Equal(t, []LoggedEntry{
+		{
+			Entry: ent,
+			Context: []zapcore.Field{
+				zap.Int("a", 1),
+				zap.Int("b", 2),
+				zap.Int("c", 3),
+				zap.Int("i", 0),
+			},
+		},
+		{
+			Entry: ent,
+			Context: []zapcore.Field{
+				zap.Int("a", 1),
+				zap.Int("b", 2),
+				zap.Int("c", 3),
+				zap.Int("d", 4),
+				zap.Int("i", 1),
+			},
+		},
+		{
+			Entry: ent,
+			Context: []zapcore.Field{
+				zap.Int("a", 1),
+				zap.Int("b", 2),
+				zap.Int("c", 3),
+				zap.Int("e", 5),
+				zap.Int("i", 2),
+			},
+		},
+	}, logs.All(), "expected no field sharing between With siblings")
+}
+
+func TestFilters(t *testing.T) {
+	logs := []LoggedEntry{
+		{
+			Entry:   zapcore.Entry{Level: zap.InfoLevel, Message: "log a"},
+			Context: []zapcore.Field{zap.String("fStr", "1"), zap.Int("a", 1)},
+		},
+		{
+			Entry:   zapcore.Entry{Level: zap.InfoLevel, Message: "log a"},
+			Context: []zapcore.Field{zap.String("fStr", "2"), zap.Int("b", 2)},
+		},
+		{
+			Entry:   zapcore.Entry{Level: zap.InfoLevel, Message: "log b"},
+			Context: []zapcore.Field{zap.Int("a", 1), zap.Int("b", 2)},
+		},
+		{
+			Entry:   zapcore.Entry{Level: zap.InfoLevel, Message: "log c"},
+			Context: []zapcore.Field{zap.Int("a", 1), zap.Namespace("ns"), zap.Int("a", 2)},
+		},
+		{
+			Entry:   zapcore.Entry{Level: zap.InfoLevel, Message: "msg 1"},
+			Context: []zapcore.Field{zap.Int("a", 1), zap.Namespace("ns")},
+		},
+		{
+			Entry:   zapcore.Entry{Level: zap.InfoLevel, Message: "any map"},
+			Context: []zapcore.Field{zap.Any("map", map[string]string{"a": "b"})},
+		},
+		{
+			Entry:   zapcore.Entry{Level: zap.InfoLevel, Message: "any slice"},
+			Context: []zapcore.Field{zap.Any("slice", []string{"a"})},
+		},
+	}
+
+	logger, sink := New(zap.InfoLevel)
+	for _, log := range logs {
+		logger.Write(log.Entry, log.Context)
+	}
+
+	tests := []struct {
+		msg      string
+		filtered *ObservedLogs
+		want     []LoggedEntry
+	}{
+		{
+			msg:      "filter by message",
+			filtered: sink.FilterMessage("log a"),
+			want:     logs[0:2],
+		},
+		{
+			msg:      "filter by field",
+			filtered: sink.FilterField(zap.String("fStr", "1")),
+			want:     logs[0:1],
+		},
+		{
+			msg:      "filter by message and field",
+			filtered: sink.FilterMessage("log a").FilterField(zap.Int("b", 2)),
+			want:     logs[1:2],
+		},
+		{
+			msg:      "filter by field with duplicate fields",
+			filtered: sink.FilterField(zap.Int("a", 2)),
+			want:     logs[3:4],
+		},
+		{
+			msg:      "filter doesn't match any messages",
+			filtered: sink.FilterMessage("no match"),
+			want:     []LoggedEntry{},
+		},
+		{
+			msg:      "filter by snippet",
+			filtered: sink.FilterMessageSnippet("log"),
+			want:     logs[0:4],
+		},
+		{
+			msg:      "filter by snippet and field",
+			filtered: sink.FilterMessageSnippet("a").FilterField(zap.Int("b", 2)),
+			want:     logs[1:2],
+		},
+		{
+			msg:      "filter for map",
+			filtered: sink.FilterField(zap.Any("map", map[string]string{"a": "b"})),
+			want:     logs[5:6],
+		},
+		{
+			msg:      "filter for slice",
+			filtered: sink.FilterField(zap.Any("slice", []string{"a"})),
+			want:     logs[6:7],
+		},
+	}
+
+	for _, tt := range tests {
+		got := tt.filtered.AllUntimed()
+		assert.Equal(t, tt.want, got, tt.msg)
+	}
+}
diff --git a/vendor/go.uber.org/zap/zaptest/timeout.go b/vendor/go.uber.org/zap/zaptest/timeout.go
new file mode 100644
index 0000000..ed24c98
--- /dev/null
+++ b/vendor/go.uber.org/zap/zaptest/timeout.go
@@ -0,0 +1,51 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zaptest
+
+import (
+	"log"
+	"os"
+	"strconv"
+	"time"
+)
+
+var _timeoutScale = 1.0
+
+// Timeout scales the provided duration by $TEST_TIMEOUT_SCALE.
+func Timeout(base time.Duration) time.Duration {
+	return time.Duration(float64(base) * _timeoutScale)
+}
+
+// Sleep scales the sleep duration by $TEST_TIMEOUT_SCALE.
+func Sleep(base time.Duration) {
+	time.Sleep(Timeout(base))
+}
+
+func init() {
+	if v := os.Getenv("TEST_TIMEOUT_SCALE"); v != "" {
+		fv, err := strconv.ParseFloat(v, 64)
+		if err != nil {
+			panic(err)
+		}
+		_timeoutScale = fv
+		log.Printf("Scaling timeouts by %vx.\n", _timeoutScale)
+	}
+}
diff --git a/vendor/go.uber.org/zap/zaptest/writer.go b/vendor/go.uber.org/zap/zaptest/writer.go
new file mode 100644
index 0000000..0b8b254
--- /dev/null
+++ b/vendor/go.uber.org/zap/zaptest/writer.go
@@ -0,0 +1,96 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zaptest
+
+import (
+	"bytes"
+	"errors"
+	"io/ioutil"
+	"strings"
+)
+
+// A Syncer is a spy for the Sync portion of zapcore.WriteSyncer.
+type Syncer struct {
+	err    error
+	called bool
+}
+
+// SetError sets the error that the Sync method will return.
+func (s *Syncer) SetError(err error) {
+	s.err = err
+}
+
+// Sync records that it was called, then returns the user-supplied error (if
+// any).
+func (s *Syncer) Sync() error {
+	s.called = true
+	return s.err
+}
+
+// Called reports whether the Sync method was called.
+func (s *Syncer) Called() bool {
+	return s.called
+}
+
+// A Discarder sends all writes to ioutil.Discard.
+type Discarder struct{ Syncer }
+
+// Write implements io.Writer.
+func (d *Discarder) Write(b []byte) (int, error) {
+	return ioutil.Discard.Write(b)
+}
+
+// FailWriter is a WriteSyncer that always returns an error on writes.
+type FailWriter struct{ Syncer }
+
+// Write implements io.Writer.
+func (w FailWriter) Write(b []byte) (int, error) {
+	return len(b), errors.New("failed")
+}
+
+// ShortWriter is a WriteSyncer whose write method never fails, but
+// nevertheless fails to the last byte of the input.
+type ShortWriter struct{ Syncer }
+
+// Write implements io.Writer.
+func (w ShortWriter) Write(b []byte) (int, error) {
+	return len(b) - 1, nil
+}
+
+// Buffer is an implementation of zapcore.WriteSyncer that sends all writes to
+// a bytes.Buffer. It has convenience methods to split the accumulated buffer
+// on newlines.
+type Buffer struct {
+	bytes.Buffer
+	Syncer
+}
+
+// Lines returns the current buffer contents, split on newlines.
+func (b *Buffer) Lines() []string {
+	output := strings.Split(b.String(), "\n")
+	return output[:len(output)-1]
+}
+
+// Stripped returns the current buffer contents with the last trailing newline
+// stripped.
+func (b *Buffer) Stripped() string {
+	return strings.TrimRight(b.String(), "\n")
+}
diff --git a/vendor/gopkg.in/natefinch/lumberjack.v2/.gitignore b/vendor/gopkg.in/natefinch/lumberjack.v2/.gitignore
new file mode 100644
index 0000000..8365624
--- /dev/null
+++ b/vendor/gopkg.in/natefinch/lumberjack.v2/.gitignore
@@ -0,0 +1,23 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test
diff --git a/vendor/gopkg.in/natefinch/lumberjack.v2/LICENSE b/vendor/gopkg.in/natefinch/lumberjack.v2/LICENSE
new file mode 100644
index 0000000..c3d4cc3
--- /dev/null
+++ b/vendor/gopkg.in/natefinch/lumberjack.v2/LICENSE
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Nate Finch 
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
\ No newline at end of file
diff --git a/vendor/gopkg.in/natefinch/lumberjack.v2/README.md b/vendor/gopkg.in/natefinch/lumberjack.v2/README.md
new file mode 100644
index 0000000..9e97154
--- /dev/null
+++ b/vendor/gopkg.in/natefinch/lumberjack.v2/README.md
@@ -0,0 +1,174 @@
+# lumberjack  [![GoDoc](https://godoc.org/gopkg.in/natefinch/lumberjack.v2?status.png)](https://godoc.org/gopkg.in/natefinch/lumberjack.v2) [![Build Status](https://drone.io/github.com/natefinch/lumberjack/status.png)](https://drone.io/github.com/natefinch/lumberjack/latest) [![Build status](https://ci.appveyor.com/api/projects/status/00gchpxtg4gkrt5d)](https://ci.appveyor.com/project/natefinch/lumberjack) [![Coverage Status](https://coveralls.io/repos/natefinch/lumberjack/badge.svg?branch=v2.0)](https://coveralls.io/r/natefinch/lumberjack?branch=v2.0)
+
+### Lumberjack is a Go package for writing logs to rolling files.
+
+Package lumberjack provides a rolling logger.
+
+Note that this is v2.0 of lumberjack, and should be imported using gopkg.in
+thusly:
+
+    import "gopkg.in/natefinch/lumberjack.v2"
+
+The package name remains simply lumberjack, and the code resides at
+https://github.com/natefinch/lumberjack under the v2.0 branch.
+
+Lumberjack is intended to be one part of a logging infrastructure.
+It is not an all-in-one solution, but instead is a pluggable
+component at the bottom of the logging stack that simply controls the files
+to which logs are written.
+
+Lumberjack plays well with any logging package that can write to an
+io.Writer, including the standard library's log package.
+
+Lumberjack assumes that only one process is writing to the output files.
+Using the same lumberjack configuration from multiple processes on the same
+machine will result in improper behavior.
+
+
+**Example**
+
+To use lumberjack with the standard library's log package, just pass it into the SetOutput function when your application starts.
+
+Code:
+
+```go
+log.SetOutput(&lumberjack.Logger{
+    Filename:   "/var/log/myapp/foo.log",
+    MaxSize:    500, // megabytes
+    MaxBackups: 3,
+    MaxAge:     28, //days
+})
+```
+
+
+
+## type Logger
+``` go
+type Logger struct {
+    // Filename is the file to write logs to.  Backup log files will be retained
+    // in the same directory.  It uses <processname>-lumberjack.log in
+    // os.TempDir() if empty.
+    Filename string `json:"filename" yaml:"filename"`
+
+    // MaxSize is the maximum size in megabytes of the log file before it gets
+    // rotated. It defaults to 100 megabytes.
+    MaxSize int `json:"maxsize" yaml:"maxsize"`
+
+    // MaxAge is the maximum number of days to retain old log files based on the
+    // timestamp encoded in their filename.  Note that a day is defined as 24
+    // hours and may not exactly correspond to calendar days due to daylight
+    // savings, leap seconds, etc. The default is not to remove old log files
+    // based on age.
+    MaxAge int `json:"maxage" yaml:"maxage"`
+
+    // MaxBackups is the maximum number of old log files to retain.  The default
+    // is to retain all old log files (though MaxAge may still cause them to get
+    // deleted.)
+    MaxBackups int `json:"maxbackups" yaml:"maxbackups"`
+
+    // LocalTime determines if the time used for formatting the timestamps in
+    // backup files is the computer's local time.  The default is to use UTC
+    // time.
+    LocalTime bool `json:"localtime" yaml:"localtime"`
+    // contains filtered or unexported fields
+}
+```
+Logger is an io.WriteCloser that writes to the specified filename.
+
+Logger opens or creates the logfile on first Write.  If the file exists and
+is less than MaxSize megabytes, lumberjack will open and append to that file.
+If the file exists and its size is >= MaxSize megabytes, the file is renamed
+by putting the current time in a timestamp in the name immediately before the
+file's extension (or the end of the filename if there's no extension). A new
+log file is then created using original filename.
+
+Whenever a write would cause the current log file exceed MaxSize megabytes,
+the current file is closed, renamed, and a new log file created with the
+original name. Thus, the filename you give Logger is always the "current" log
+file.
+
+Backups use the log file name given to Logger, in the form `name-timestamp.ext`
+where name is the filename without the extension, timestamp is the time at which
+the log was rotated formatted with the time.Time format of
+`2006-01-02T15-04-05.000` and the extension is the original extension.  For
+example, if your Logger.Filename is `/var/log/foo/server.log`, a backup created
+at 6:30pm on Nov 11 2016 would use the filename
+`/var/log/foo/server-2016-11-04T18-30-00.000.log`
+
+### Cleaning Up Old Log Files
+Whenever a new logfile gets created, old log files may be deleted.  The most
+recent files according to the encoded timestamp will be retained, up to a
+number equal to MaxBackups (or all of them if MaxBackups is 0).  Any files
+with an encoded timestamp older than MaxAge days are deleted, regardless of
+MaxBackups.  Note that the time encoded in the timestamp is the rotation
+time, which may differ from the last time that file was written to.
+
+If MaxBackups and MaxAge are both 0, no old log files will be deleted.
+
+
+
+
+
+
+
+
+
+
+
+### func (\*Logger) Close
+``` go
+func (l *Logger) Close() error
+```
+Close implements io.Closer, and closes the current logfile.
+
+
+
+### func (\*Logger) Rotate
+``` go
+func (l *Logger) Rotate() error
+```
+Rotate causes Logger to close the existing log file and immediately create a
+new one.  This is a helper function for applications that want to initiate
+rotations outside of the normal rotation rules, such as in response to
+SIGHUP.  After rotating, this initiates a cleanup of old log files according
+to the normal rules.
+
+**Example**
+
+Example of how to rotate in response to SIGHUP.
+
+Code:
+
+```go
+l := &lumberjack.Logger{}
+log.SetOutput(l)
+c := make(chan os.Signal, 1)
+signal.Notify(c, syscall.SIGHUP)
+
+go func() {
+    for {
+        <-c
+        l.Rotate()
+    }
+}()
+```
+
+### func (\*Logger) Write
+``` go
+func (l *Logger) Write(p []byte) (n int, err error)
+```
+Write implements io.Writer.  If a write would cause the log file to be larger
+than MaxSize, the file is closed, renamed to include a timestamp of the
+current time, and a new log file is created using the original log file name.
+If the length of the write is greater than MaxSize, an error is returned.
+
+
+
+
+
+
+
+
+
+- - -
+Generated by [godoc2md](http://godoc.org/github.com/davecheney/godoc2md)
diff --git a/vendor/gopkg.in/natefinch/lumberjack.v2/chown.go b/vendor/gopkg.in/natefinch/lumberjack.v2/chown.go
new file mode 100644
index 0000000..11d0669
--- /dev/null
+++ b/vendor/gopkg.in/natefinch/lumberjack.v2/chown.go
@@ -0,0 +1,11 @@
+// +build !linux
+
+package lumberjack
+
+import (
+	"os"
+)
+
+func chown(_ string, _ os.FileInfo) error {
+	return nil
+}
diff --git a/vendor/gopkg.in/natefinch/lumberjack.v2/chown_linux.go b/vendor/gopkg.in/natefinch/lumberjack.v2/chown_linux.go
new file mode 100644
index 0000000..2758ec9
--- /dev/null
+++ b/vendor/gopkg.in/natefinch/lumberjack.v2/chown_linux.go
@@ -0,0 +1,19 @@
+package lumberjack
+
+import (
+	"os"
+	"syscall"
+)
+
+// os_Chown is a var so we can mock it out during tests.
+var os_Chown = os.Chown
+
+func chown(name string, info os.FileInfo) error {
+	f, err := os.OpenFile(name, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, info.Mode())
+	if err != nil {
+		return err
+	}
+	f.Close()
+	stat := info.Sys().(*syscall.Stat_t)
+	return os_Chown(name, int(stat.Uid), int(stat.Gid))
+}
diff --git a/vendor/gopkg.in/natefinch/lumberjack.v2/example_test.go b/vendor/gopkg.in/natefinch/lumberjack.v2/example_test.go
new file mode 100644
index 0000000..bf689fd
--- /dev/null
+++ b/vendor/gopkg.in/natefinch/lumberjack.v2/example_test.go
@@ -0,0 +1,18 @@
+package lumberjack_test
+
+import (
+	"log"
+
+	"gopkg.in/natefinch/lumberjack.v2"
+)
+
+// To use lumberjack with the standard library's log package, just pass it into
+// the SetOutput function when your application starts.
+func Example() {
+	log.SetOutput(&lumberjack.Logger{
+		Filename:   "/var/log/myapp/foo.log",
+		MaxSize:    500, // megabytes
+		MaxBackups: 3,
+		MaxAge:     28, // days
+	})
+}
diff --git a/vendor/gopkg.in/natefinch/lumberjack.v2/linux_test.go b/vendor/gopkg.in/natefinch/lumberjack.v2/linux_test.go
new file mode 100644
index 0000000..2bd1684
--- /dev/null
+++ b/vendor/gopkg.in/natefinch/lumberjack.v2/linux_test.go
@@ -0,0 +1,205 @@
+// +build linux
+
+package lumberjack
+
+import (
+	"os"
+	"syscall"
+	"testing"
+	"time"
+)
+
+func TestMaintainMode(t *testing.T) {
+	currentTime = fakeTime
+	dir := makeTempDir("TestMaintainMode", t)
+	defer os.RemoveAll(dir)
+
+	filename := logFile(dir)
+
+	mode := os.FileMode(0600)
+	f, err := os.OpenFile(filename, os.O_CREATE|os.O_RDWR, mode)
+	isNil(err, t)
+	f.Close()
+
+	l := &Logger{
+		Filename:   filename,
+		MaxBackups: 1,
+		MaxSize:    100, // megabytes
+	}
+	defer l.Close()
+	b := []byte("boo!")
+	n, err := l.Write(b)
+	isNil(err, t)
+	equals(len(b), n, t)
+
+	newFakeTime()
+
+	err = l.Rotate()
+	isNil(err, t)
+
+	filename2 := backupFile(dir)
+	info, err := os.Stat(filename)
+	isNil(err, t)
+	info2, err := os.Stat(filename2)
+	isNil(err, t)
+	equals(mode, info.Mode(), t)
+	equals(mode, info2.Mode(), t)
+}
+
+func TestMaintainOwner(t *testing.T) {
+	fakeFS := newFakeFS()
+	os_Chown = fakeFS.Chown
+	os_Stat = fakeFS.Stat
+	defer func() {
+		os_Chown = os.Chown
+		os_Stat = os.Stat
+	}()
+	currentTime = fakeTime
+	dir := makeTempDir("TestMaintainOwner", t)
+	defer os.RemoveAll(dir)
+
+	filename := logFile(dir)
+
+	f, err := os.OpenFile(filename, os.O_CREATE|os.O_RDWR, 0644)
+	isNil(err, t)
+	f.Close()
+
+	l := &Logger{
+		Filename:   filename,
+		MaxBackups: 1,
+		MaxSize:    100, // megabytes
+	}
+	defer l.Close()
+	b := []byte("boo!")
+	n, err := l.Write(b)
+	isNil(err, t)
+	equals(len(b), n, t)
+
+	newFakeTime()
+
+	err = l.Rotate()
+	isNil(err, t)
+
+	equals(555, fakeFS.files[filename].uid, t)
+	equals(666, fakeFS.files[filename].gid, t)
+}
+
+func TestCompressMaintainMode(t *testing.T) {
+	currentTime = fakeTime
+
+	dir := makeTempDir("TestCompressMaintainMode", t)
+	defer os.RemoveAll(dir)
+
+	filename := logFile(dir)
+
+	mode := os.FileMode(0600)
+	f, err := os.OpenFile(filename, os.O_CREATE|os.O_RDWR, mode)
+	isNil(err, t)
+	f.Close()
+
+	l := &Logger{
+		Compress: true,
+		Filename:   filename,
+		MaxBackups: 1,
+		MaxSize:    100, // megabytes
+	}
+	defer l.Close()
+	b := []byte("boo!")
+	n, err := l.Write(b)
+	isNil(err, t)
+	equals(len(b), n, t)
+
+	newFakeTime()
+
+	err = l.Rotate()
+	isNil(err, t)
+
+	// we need to wait a little bit since the files get compressed on a different
+	// goroutine.
+	<-time.After(10 * time.Millisecond)
+
+	// a compressed version of the log file should now exist with the correct
+	// mode.
+	filename2 := backupFile(dir)
+	info, err := os.Stat(filename)
+	isNil(err, t)
+	info2, err := os.Stat(filename2+compressSuffix)
+	isNil(err, t)
+	equals(mode, info.Mode(), t)
+	equals(mode, info2.Mode(), t)
+}
+
+func TestCompressMaintainOwner(t *testing.T) {
+	fakeFS := newFakeFS()
+	os_Chown = fakeFS.Chown
+	os_Stat = fakeFS.Stat
+	defer func() {
+		os_Chown = os.Chown
+		os_Stat = os.Stat
+	}()
+	currentTime = fakeTime
+	dir := makeTempDir("TestCompressMaintainOwner", t)
+	defer os.RemoveAll(dir)
+
+	filename := logFile(dir)
+
+	f, err := os.OpenFile(filename, os.O_CREATE|os.O_RDWR, 0644)
+	isNil(err, t)
+	f.Close()
+
+	l := &Logger{
+		Compress:   true,
+		Filename:   filename,
+		MaxBackups: 1,
+		MaxSize:    100, // megabytes
+	}
+	defer l.Close()
+	b := []byte("boo!")
+	n, err := l.Write(b)
+	isNil(err, t)
+	equals(len(b), n, t)
+
+	newFakeTime()
+
+	err = l.Rotate()
+	isNil(err, t)
+
+	// we need to wait a little bit since the files get compressed on a different
+	// goroutine.
+	<-time.After(10 * time.Millisecond)
+
+	// a compressed version of the log file should now exist with the correct
+	// owner.
+	filename2 := backupFile(dir)
+	equals(555, fakeFS.files[filename2+compressSuffix].uid, t)
+	equals(666, fakeFS.files[filename2+compressSuffix].gid, t)
+}
+
+type fakeFile struct {
+	uid int
+	gid int
+}
+
+type fakeFS struct {
+	files map[string]fakeFile
+}
+
+func newFakeFS() *fakeFS {
+	return &fakeFS{files: make(map[string]fakeFile)}
+}
+
+func (fs *fakeFS) Chown(name string, uid, gid int) error {
+	fs.files[name] = fakeFile{uid: uid, gid: gid}
+	return nil
+}
+
+func (fs *fakeFS) Stat(name string) (os.FileInfo, error) {
+	info, err := os.Stat(name)
+	if err != nil {
+		return nil, err
+	}
+	stat := info.Sys().(*syscall.Stat_t)
+	stat.Uid = 555
+	stat.Gid = 666
+	return info, nil
+}
diff --git a/vendor/gopkg.in/natefinch/lumberjack.v2/lumberjack.go b/vendor/gopkg.in/natefinch/lumberjack.v2/lumberjack.go
new file mode 100644
index 0000000..ca19da4
--- /dev/null
+++ b/vendor/gopkg.in/natefinch/lumberjack.v2/lumberjack.go
@@ -0,0 +1,541 @@
+// Package lumberjack provides a rolling logger.
+//
+// Note that this is v2.0 of lumberjack, and should be imported using gopkg.in
+// thusly:
+//
+//   import "gopkg.in/natefinch/lumberjack.v2"
+//
+// The package name remains simply lumberjack, and the code resides at
+// https://github.com/natefinch/lumberjack under the v2.0 branch.
+//
+// Lumberjack is intended to be one part of a logging infrastructure.
+// It is not an all-in-one solution, but instead is a pluggable
+// component at the bottom of the logging stack that simply controls the files
+// to which logs are written.
+//
+// Lumberjack plays well with any logging package that can write to an
+// io.Writer, including the standard library's log package.
+//
+// Lumberjack assumes that only one process is writing to the output files.
+// Using the same lumberjack configuration from multiple processes on the same
+// machine will result in improper behavior.
+package lumberjack
+
+import (
+	"compress/gzip"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+)
+
+const (
+	backupTimeFormat = "2006-01-02T15-04-05.000"
+	compressSuffix   = ".gz"
+	defaultMaxSize   = 100
+)
+
+// ensure we always implement io.WriteCloser
+var _ io.WriteCloser = (*Logger)(nil)
+
+// Logger is an io.WriteCloser that writes to the specified filename.
+//
+// Logger opens or creates the logfile on first Write.  If the file exists and
+// is less than MaxSize megabytes, lumberjack will open and append to that file.
+// If the file exists and its size is >= MaxSize megabytes, the file is renamed
+// by putting the current time in a timestamp in the name immediately before the
+// file's extension (or the end of the filename if there's no extension). A new
+// log file is then created using original filename.
+//
+// Whenever a write would cause the current log file exceed MaxSize megabytes,
+// the current file is closed, renamed, and a new log file created with the
+// original name. Thus, the filename you give Logger is always the "current" log
+// file.
+//
+// Backups use the log file name given to Logger, in the form
+// `name-timestamp.ext` where name is the filename without the extension,
+// timestamp is the time at which the log was rotated formatted with the
+// time.Time format of `2006-01-02T15-04-05.000` and the extension is the
+// original extension.  For example, if your Logger.Filename is
+// `/var/log/foo/server.log`, a backup created at 6:30pm on Nov 11 2016 would
+// use the filename `/var/log/foo/server-2016-11-04T18-30-00.000.log`
+//
+// Cleaning Up Old Log Files
+//
+// Whenever a new logfile gets created, old log files may be deleted.  The most
+// recent files according to the encoded timestamp will be retained, up to a
+// number equal to MaxBackups (or all of them if MaxBackups is 0).  Any files
+// with an encoded timestamp older than MaxAge days are deleted, regardless of
+// MaxBackups.  Note that the time encoded in the timestamp is the rotation
+// time, which may differ from the last time that file was written to.
+//
+// If MaxBackups and MaxAge are both 0, no old log files will be deleted.
+type Logger struct {
+	// Filename is the file to write logs to.  Backup log files will be retained
+	// in the same directory.  It uses <processname>-lumberjack.log in
+	// os.TempDir() if empty.
+	Filename string `json:"filename" yaml:"filename"`
+
+	// MaxSize is the maximum size in megabytes of the log file before it gets
+	// rotated. It defaults to 100 megabytes.
+	MaxSize int `json:"maxsize" yaml:"maxsize"`
+
+	// MaxAge is the maximum number of days to retain old log files based on the
+	// timestamp encoded in their filename.  Note that a day is defined as 24
+	// hours and may not exactly correspond to calendar days due to daylight
+	// savings, leap seconds, etc. The default is not to remove old log files
+	// based on age.
+	MaxAge int `json:"maxage" yaml:"maxage"`
+
+	// MaxBackups is the maximum number of old log files to retain.  The default
+	// is to retain all old log files (though MaxAge may still cause them to get
+	// deleted.)
+	MaxBackups int `json:"maxbackups" yaml:"maxbackups"`
+
+	// LocalTime determines if the time used for formatting the timestamps in
+	// backup files is the computer's local time.  The default is to use UTC
+	// time.
+	LocalTime bool `json:"localtime" yaml:"localtime"`
+
+	// Compress determines if the rotated log files should be compressed
+	// using gzip.
+	Compress bool `json:"compress" yaml:"compress"`
+
+	size int64
+	file *os.File
+	mu   sync.Mutex
+
+	millCh    chan bool
+	startMill sync.Once
+}
+
+var (
+	// currentTime exists so it can be mocked out by tests.
+	currentTime = time.Now
+
+	// os_Stat exists so it can be mocked out by tests.
+	os_Stat = os.Stat
+
+	// megabyte is the conversion factor between MaxSize and bytes.  It is a
+	// variable so tests can mock it out and not need to write megabytes of data
+	// to disk.
+	megabyte = 1024 * 1024
+)
+
+// Write implements io.Writer.  If a write would cause the log file to be larger
+// than MaxSize, the file is closed, renamed to include a timestamp of the
+// current time, and a new log file is created using the original log file name.
+// If the length of the write is greater than MaxSize, an error is returned.
+func (l *Logger) Write(p []byte) (n int, err error) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	writeLen := int64(len(p))
+	if writeLen > l.max() {
+		return 0, fmt.Errorf(
+			"write length %d exceeds maximum file size %d", writeLen, l.max(),
+		)
+	}
+
+	if l.file == nil {
+		if err = l.openExistingOrNew(len(p)); err != nil {
+			return 0, err
+		}
+	}
+
+	if l.size+writeLen > l.max() {
+		if err := l.rotate(); err != nil {
+			return 0, err
+		}
+	}
+
+	n, err = l.file.Write(p)
+	l.size += int64(n)
+
+	return n, err
+}
+
+// Close implements io.Closer, and closes the current logfile.
+func (l *Logger) Close() error {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	return l.close()
+}
+
+// close closes the file if it is open.
+func (l *Logger) close() error {
+	if l.file == nil {
+		return nil
+	}
+	err := l.file.Close()
+	l.file = nil
+	return err
+}
+
+// Rotate causes Logger to close the existing log file and immediately create a
+// new one.  This is a helper function for applications that want to initiate
+// rotations outside of the normal rotation rules, such as in response to
+// SIGHUP.  After rotating, this initiates compression and removal of old log
+// files according to the configuration.
+func (l *Logger) Rotate() error {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	return l.rotate()
+}
+
+// rotate closes the current file, moves it aside with a timestamp in the name,
+// (if it exists), opens a new file with the original filename, and then runs
+// post-rotation processing and removal.
+func (l *Logger) rotate() error {
+	if err := l.close(); err != nil {
+		return err
+	}
+	if err := l.openNew(); err != nil {
+		return err
+	}
+	l.mill()
+	return nil
+}
+
+// openNew opens a new log file for writing, moving any old log file out of the
+// way.  This methods assumes the file has already been closed.
+func (l *Logger) openNew() error {
+	err := os.MkdirAll(l.dir(), 0744)
+	if err != nil {
+		return fmt.Errorf("can't make directories for new logfile: %s", err)
+	}
+
+	name := l.filename()
+	mode := os.FileMode(0644)
+	info, err := os_Stat(name)
+	if err == nil {
+		// Copy the mode off the old logfile.
+		mode = info.Mode()
+		// move the existing file
+		newname := backupName(name, l.LocalTime)
+		if err := os.Rename(name, newname); err != nil {
+			return fmt.Errorf("can't rename log file: %s", err)
+		}
+
+		// this is a no-op anywhere but linux
+		if err := chown(name, info); err != nil {
+			return err
+		}
+	}
+
+	// we use truncate here because this should only get called when we've moved
+	// the file ourselves. if someone else creates the file in the meantime,
+	// just wipe out the contents.
+	f, err := os.OpenFile(name, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, mode)
+	if err != nil {
+		return fmt.Errorf("can't open new logfile: %s", err)
+	}
+	l.file = f
+	l.size = 0
+	return nil
+}
+
+// backupName creates a new filename from the given name, inserting a timestamp
+// between the filename and the extension, using the local time if requested
+// (otherwise UTC).
+func backupName(name string, local bool) string {
+	dir := filepath.Dir(name)
+	filename := filepath.Base(name)
+	ext := filepath.Ext(filename)
+	prefix := filename[:len(filename)-len(ext)]
+	t := currentTime()
+	if !local {
+		t = t.UTC()
+	}
+
+	timestamp := t.Format(backupTimeFormat)
+	return filepath.Join(dir, fmt.Sprintf("%s-%s%s", prefix, timestamp, ext))
+}
+
+// openExistingOrNew opens the logfile if it exists and if the current write
+// would not put it over MaxSize.  If there is no such file or the write would
+// put it over the MaxSize, a new file is created.
+func (l *Logger) openExistingOrNew(writeLen int) error {
+	l.mill()
+
+	filename := l.filename()
+	info, err := os_Stat(filename)
+	if os.IsNotExist(err) {
+		return l.openNew()
+	}
+	if err != nil {
+		return fmt.Errorf("error getting log file info: %s", err)
+	}
+
+	if info.Size()+int64(writeLen) >= l.max() {
+		return l.rotate()
+	}
+
+	file, err := os.OpenFile(filename, os.O_APPEND|os.O_WRONLY, 0644)
+	if err != nil {
+		// if we fail to open the old log file for some reason, just ignore
+		// it and open a new log file.
+		return l.openNew()
+	}
+	l.file = file
+	l.size = info.Size()
+	return nil
+}
+
+// genFilename generates the name of the logfile from the current time.
+func (l *Logger) filename() string {
+	if l.Filename != "" {
+		return l.Filename
+	}
+	name := filepath.Base(os.Args[0]) + "-lumberjack.log"
+	return filepath.Join(os.TempDir(), name)
+}
+
+// millRunOnce performs compression and removal of stale log files.
+// Log files are compressed if enabled via configuration and old log
+// files are removed, keeping at most l.MaxBackups files, as long as
+// none of them are older than MaxAge.
+func (l *Logger) millRunOnce() error {
+	if l.MaxBackups == 0 && l.MaxAge == 0 && !l.Compress {
+		return nil
+	}
+
+	files, err := l.oldLogFiles()
+	if err != nil {
+		return err
+	}
+
+	var compress, remove []logInfo
+
+	if l.MaxBackups > 0 && l.MaxBackups < len(files) {
+		preserved := make(map[string]bool)
+		var remaining []logInfo
+		for _, f := range files {
+			// Only count the uncompressed log file or the
+			// compressed log file, not both.
+			fn := f.Name()
+			if strings.HasSuffix(fn, compressSuffix) {
+				fn = fn[:len(fn)-len(compressSuffix)]
+			}
+			preserved[fn] = true
+
+			if len(preserved) > l.MaxBackups {
+				remove = append(remove, f)
+			} else {
+				remaining = append(remaining, f)
+			}
+		}
+		files = remaining
+	}
+	if l.MaxAge > 0 {
+		diff := time.Duration(int64(24*time.Hour) * int64(l.MaxAge))
+		cutoff := currentTime().Add(-1 * diff)
+
+		var remaining []logInfo
+		for _, f := range files {
+			if f.timestamp.Before(cutoff) {
+				remove = append(remove, f)
+			} else {
+				remaining = append(remaining, f)
+			}
+		}
+		files = remaining
+	}
+
+	if l.Compress {
+		for _, f := range files {
+			if !strings.HasSuffix(f.Name(), compressSuffix) {
+				compress = append(compress, f)
+			}
+		}
+	}
+
+	for _, f := range remove {
+		errRemove := os.Remove(filepath.Join(l.dir(), f.Name()))
+		if err == nil && errRemove != nil {
+			err = errRemove
+		}
+	}
+	for _, f := range compress {
+		fn := filepath.Join(l.dir(), f.Name())
+		errCompress := compressLogFile(fn, fn+compressSuffix)
+		if err == nil && errCompress != nil {
+			err = errCompress
+		}
+	}
+
+	return err
+}
+
+// millRun runs in a goroutine to manage post-rotation compression and removal
+// of old log files.
+func (l *Logger) millRun() {
+	for _ = range l.millCh {
+		// what am I going to do, log this?
+		_ = l.millRunOnce()
+	}
+}
+
+// mill performs post-rotation compression and removal of stale log files,
+// starting the mill goroutine if necessary.
+func (l *Logger) mill() {
+	l.startMill.Do(func() {
+		l.millCh = make(chan bool, 1)
+		go l.millRun()
+	})
+	select {
+	case l.millCh <- true:
+	default:
+	}
+}
+
+// oldLogFiles returns the list of backup log files stored in the same
+// directory as the current log file, sorted by ModTime
+func (l *Logger) oldLogFiles() ([]logInfo, error) {
+	files, err := ioutil.ReadDir(l.dir())
+	if err != nil {
+		return nil, fmt.Errorf("can't read log file directory: %s", err)
+	}
+	logFiles := []logInfo{}
+
+	prefix, ext := l.prefixAndExt()
+
+	for _, f := range files {
+		if f.IsDir() {
+			continue
+		}
+		if t, err := l.timeFromName(f.Name(), prefix, ext); err == nil {
+			logFiles = append(logFiles, logInfo{t, f})
+			continue
+		}
+		if t, err := l.timeFromName(f.Name(), prefix, ext+compressSuffix); err == nil {
+			logFiles = append(logFiles, logInfo{t, f})
+			continue
+		}
+		// error parsing means that the suffix at the end was not generated
+		// by lumberjack, and therefore it's not a backup file.
+	}
+
+	sort.Sort(byFormatTime(logFiles))
+
+	return logFiles, nil
+}
+
+// timeFromName extracts the formatted time from the filename by stripping off
+// the filename's prefix and extension. This prevents someone's filename from
+// confusing time.parse.
+func (l *Logger) timeFromName(filename, prefix, ext string) (time.Time, error) {
+	if !strings.HasPrefix(filename, prefix) {
+		return time.Time{}, errors.New("mismatched prefix")
+	}
+	if !strings.HasSuffix(filename, ext) {
+		return time.Time{}, errors.New("mismatched extension")
+	}
+	ts := filename[len(prefix) : len(filename)-len(ext)]
+	return time.Parse(backupTimeFormat, ts)
+}
+
+// max returns the maximum size in bytes of log files before rolling.
+func (l *Logger) max() int64 {
+	if l.MaxSize == 0 {
+		return int64(defaultMaxSize * megabyte)
+	}
+	return int64(l.MaxSize) * int64(megabyte)
+}
+
+// dir returns the directory for the current filename.
+func (l *Logger) dir() string {
+	return filepath.Dir(l.filename())
+}
+
+// prefixAndExt returns the filename part and extension part from the Logger's
+// filename.
+func (l *Logger) prefixAndExt() (prefix, ext string) {
+	filename := filepath.Base(l.filename())
+	ext = filepath.Ext(filename)
+	prefix = filename[:len(filename)-len(ext)] + "-"
+	return prefix, ext
+}
+
+// compressLogFile compresses the given log file, removing the
+// uncompressed log file if successful.
+func compressLogFile(src, dst string) (err error) {
+	f, err := os.Open(src)
+	if err != nil {
+		return fmt.Errorf("failed to open log file: %v", err)
+	}
+	defer f.Close()
+
+	fi, err := os_Stat(src)
+	if err != nil {
+		return fmt.Errorf("failed to stat log file: %v", err)
+	}
+
+	if err := chown(dst, fi); err != nil {
+		return fmt.Errorf("failed to chown compressed log file: %v", err)
+	}
+
+	// If this file already exists, we presume it was created by
+	// a previous attempt to compress the log file.
+	gzf, err := os.OpenFile(dst, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, fi.Mode())
+	if err != nil {
+		return fmt.Errorf("failed to open compressed log file: %v", err)
+	}
+	defer gzf.Close()
+
+	gz := gzip.NewWriter(gzf)
+
+	defer func() {
+		if err != nil {
+			os.Remove(dst)
+			err = fmt.Errorf("failed to compress log file: %v", err)
+		}
+	}()
+
+	if _, err := io.Copy(gz, f); err != nil {
+		return err
+	}
+	if err := gz.Close(); err != nil {
+		return err
+	}
+	if err := gzf.Close(); err != nil {
+		return err
+	}
+
+	if err := f.Close(); err != nil {
+		return err
+	}
+	if err := os.Remove(src); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// logInfo is a convenience struct to return the filename and its embedded
+// timestamp.
+type logInfo struct {
+	timestamp time.Time
+	os.FileInfo
+}
+
+// byFormatTime sorts by newest time formatted in the name.
+type byFormatTime []logInfo
+
+func (b byFormatTime) Less(i, j int) bool {
+	return b[i].timestamp.After(b[j].timestamp)
+}
+
+func (b byFormatTime) Swap(i, j int) {
+	b[i], b[j] = b[j], b[i]
+}
+
+func (b byFormatTime) Len() int {
+	return len(b)
+}
diff --git a/vendor/gopkg.in/natefinch/lumberjack.v2/lumberjack_test.go b/vendor/gopkg.in/natefinch/lumberjack.v2/lumberjack_test.go
new file mode 100644
index 0000000..58e165f
--- /dev/null
+++ b/vendor/gopkg.in/natefinch/lumberjack.v2/lumberjack_test.go
@@ -0,0 +1,816 @@
+package lumberjack
+
+import (
+	"bytes"
+	"compress/gzip"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/BurntSushi/toml"
+	"gopkg.in/yaml.v2"
+)
+
+// !!!NOTE!!!
+//
+// Running these tests in parallel will almost certainly cause sporadic (or even
+// regular) failures, because they're all messing with the same global variable
+// that controls the logic's mocked time.Now.  So... don't do that.
+
+// Since all the tests uses the time to determine filenames etc, we need to
+// control the wall clock as much as possible, which means having a wall clock
+// that doesn't change unless we want it to.
+var fakeCurrentTime = time.Now()
+
+func fakeTime() time.Time {
+	return fakeCurrentTime
+}
+
+func TestNewFile(t *testing.T) {
+	currentTime = fakeTime
+
+	dir := makeTempDir("TestNewFile", t)
+	defer os.RemoveAll(dir)
+	l := &Logger{
+		Filename: logFile(dir),
+	}
+	defer l.Close()
+	b := []byte("boo!")
+	n, err := l.Write(b)
+	isNil(err, t)
+	equals(len(b), n, t)
+	existsWithContent(logFile(dir), b, t)
+	fileCount(dir, 1, t)
+}
+
+func TestOpenExisting(t *testing.T) {
+	currentTime = fakeTime
+	dir := makeTempDir("TestOpenExisting", t)
+	defer os.RemoveAll(dir)
+
+	filename := logFile(dir)
+	data := []byte("foo!")
+	err := ioutil.WriteFile(filename, data, 0644)
+	isNil(err, t)
+	existsWithContent(filename, data, t)
+
+	l := &Logger{
+		Filename: filename,
+	}
+	defer l.Close()
+	b := []byte("boo!")
+	n, err := l.Write(b)
+	isNil(err, t)
+	equals(len(b), n, t)
+
+	// make sure the file got appended
+	existsWithContent(filename, append(data, b...), t)
+
+	// make sure no other files were created
+	fileCount(dir, 1, t)
+}
+
+func TestWriteTooLong(t *testing.T) {
+	currentTime = fakeTime
+	megabyte = 1
+	dir := makeTempDir("TestWriteTooLong", t)
+	defer os.RemoveAll(dir)
+	l := &Logger{
+		Filename: logFile(dir),
+		MaxSize:  5,
+	}
+	defer l.Close()
+	b := []byte("booooooooooooooo!")
+	n, err := l.Write(b)
+	notNil(err, t)
+	equals(0, n, t)
+	equals(err.Error(),
+		fmt.Sprintf("write length %d exceeds maximum file size %d", len(b), l.MaxSize), t)
+	_, err = os.Stat(logFile(dir))
+	assert(os.IsNotExist(err), t, "File exists, but should not have been created")
+}
+
+func TestMakeLogDir(t *testing.T) {
+	currentTime = fakeTime
+	dir := time.Now().Format("TestMakeLogDir" + backupTimeFormat)
+	dir = filepath.Join(os.TempDir(), dir)
+	defer os.RemoveAll(dir)
+	filename := logFile(dir)
+	l := &Logger{
+		Filename: filename,
+	}
+	defer l.Close()
+	b := []byte("boo!")
+	n, err := l.Write(b)
+	isNil(err, t)
+	equals(len(b), n, t)
+	existsWithContent(logFile(dir), b, t)
+	fileCount(dir, 1, t)
+}
+
+func TestDefaultFilename(t *testing.T) {
+	currentTime = fakeTime
+	dir := os.TempDir()
+	filename := filepath.Join(dir, filepath.Base(os.Args[0])+"-lumberjack.log")
+	defer os.Remove(filename)
+	l := &Logger{}
+	defer l.Close()
+	b := []byte("boo!")
+	n, err := l.Write(b)
+
+	isNil(err, t)
+	equals(len(b), n, t)
+	existsWithContent(filename, b, t)
+}
+
+func TestAutoRotate(t *testing.T) {
+	currentTime = fakeTime
+	megabyte = 1
+
+	dir := makeTempDir("TestAutoRotate", t)
+	defer os.RemoveAll(dir)
+
+	filename := logFile(dir)
+	l := &Logger{
+		Filename: filename,
+		MaxSize:  10,
+	}
+	defer l.Close()
+	b := []byte("boo!")
+	n, err := l.Write(b)
+	isNil(err, t)
+	equals(len(b), n, t)
+
+	existsWithContent(filename, b, t)
+	fileCount(dir, 1, t)
+
+	newFakeTime()
+
+	b2 := []byte("foooooo!")
+	n, err = l.Write(b2)
+	isNil(err, t)
+	equals(len(b2), n, t)
+
+	// the old logfile should be moved aside and the main logfile should have
+	// only the last write in it.
+	existsWithContent(filename, b2, t)
+
+	// the backup file will use the current fake time and have the old contents.
+	existsWithContent(backupFile(dir), b, t)
+
+	fileCount(dir, 2, t)
+}
+
+func TestFirstWriteRotate(t *testing.T) {
+	currentTime = fakeTime
+	megabyte = 1
+	dir := makeTempDir("TestFirstWriteRotate", t)
+	defer os.RemoveAll(dir)
+
+	filename := logFile(dir)
+	l := &Logger{
+		Filename: filename,
+		MaxSize:  10,
+	}
+	defer l.Close()
+
+	start := []byte("boooooo!")
+	err := ioutil.WriteFile(filename, start, 0600)
+	isNil(err, t)
+
+	newFakeTime()
+
+	// this would make us rotate
+	b := []byte("fooo!")
+	n, err := l.Write(b)
+	isNil(err, t)
+	equals(len(b), n, t)
+
+	existsWithContent(filename, b, t)
+	existsWithContent(backupFile(dir), start, t)
+
+	fileCount(dir, 2, t)
+}
+
+func TestMaxBackups(t *testing.T) {
+	currentTime = fakeTime
+	megabyte = 1
+	dir := makeTempDir("TestMaxBackups", t)
+	defer os.RemoveAll(dir)
+
+	filename := logFile(dir)
+	l := &Logger{
+		Filename:   filename,
+		MaxSize:    10,
+		MaxBackups: 1,
+	}
+	defer l.Close()
+	b := []byte("boo!")
+	n, err := l.Write(b)
+	isNil(err, t)
+	equals(len(b), n, t)
+
+	existsWithContent(filename, b, t)
+	fileCount(dir, 1, t)
+
+	newFakeTime()
+
+	// this will put us over the max
+	b2 := []byte("foooooo!")
+	n, err = l.Write(b2)
+	isNil(err, t)
+	equals(len(b2), n, t)
+
+	// this will use the new fake time
+	secondFilename := backupFile(dir)
+	existsWithContent(secondFilename, b, t)
+
+	// make sure the old file still exists with the same content.
+	existsWithContent(filename, b2, t)
+
+	fileCount(dir, 2, t)
+
+	newFakeTime()
+
+	// this will make us rotate again
+	b3 := []byte("baaaaaar!")
+	n, err = l.Write(b3)
+	isNil(err, t)
+	equals(len(b3), n, t)
+
+	// this will use the new fake time
+	thirdFilename := backupFile(dir)
+	existsWithContent(thirdFilename, b2, t)
+
+	existsWithContent(filename, b3, t)
+
+	// we need to wait a little bit since the files get deleted on a different
+	// goroutine.
+	<-time.After(time.Millisecond * 10)
+
+	// should only have two files in the dir still
+	fileCount(dir, 2, t)
+
+	// second file name should still exist
+	existsWithContent(thirdFilename, b2, t)
+
+	// should have deleted the first backup
+	notExist(secondFilename, t)
+
+	// now test that we don't delete directories or non-logfile files
+
+	newFakeTime()
+
+	// create a file that is close to but different from the logfile name.
+	// It shouldn't get caught by our deletion filters.
+	notlogfile := logFile(dir) + ".foo"
+	err = ioutil.WriteFile(notlogfile, []byte("data"), 0644)
+	isNil(err, t)
+
+	// Make a directory that exactly matches our log file filters... it still
+	// shouldn't get caught by the deletion filter since it's a directory.
+	notlogfiledir := backupFile(dir)
+	err = os.Mkdir(notlogfiledir, 0700)
+	isNil(err, t)
+
+	newFakeTime()
+
+	// this will use the new fake time
+	fourthFilename := backupFile(dir)
+
+	// Create a log file that is/was being compressed - this should
+	// not be counted since both the compressed and the uncompressed
+	// log files still exist.
+	compLogFile := fourthFilename+compressSuffix
+	err = ioutil.WriteFile(compLogFile, []byte("compress"), 0644)
+	isNil(err, t)
+
+	// this will make us rotate again
+	b4 := []byte("baaaaaaz!")
+	n, err = l.Write(b4)
+	isNil(err, t)
+	equals(len(b4), n, t)
+
+	existsWithContent(fourthFilename, b3, t)
+	existsWithContent(fourthFilename+compressSuffix, []byte("compress"), t)
+
+	// we need to wait a little bit since the files get deleted on a different
+	// goroutine.
+	<-time.After(time.Millisecond * 10)
+
+	// We should have four things in the directory now - the 2 log files, the
+	// not log file, and the directory
+	fileCount(dir, 5, t)
+
+	// third file name should still exist
+	existsWithContent(filename, b4, t)
+
+	existsWithContent(fourthFilename, b3, t)
+
+	// should have deleted the first filename
+	notExist(thirdFilename, t)
+
+	// the not-a-logfile should still exist
+	exists(notlogfile, t)
+
+	// the directory
+	exists(notlogfiledir, t)
+}
+
+func TestCleanupExistingBackups(t *testing.T) {
+	// test that if we start with more backup files than we're supposed to have
+	// in total, that extra ones get cleaned up when we rotate.
+
+	currentTime = fakeTime
+	megabyte = 1
+
+	dir := makeTempDir("TestCleanupExistingBackups", t)
+	defer os.RemoveAll(dir)
+
+	// make 3 backup files
+
+	data := []byte("data")
+	backup := backupFile(dir)
+	err := ioutil.WriteFile(backup, data, 0644)
+	isNil(err, t)
+
+	newFakeTime()
+
+	backup = backupFile(dir)
+	err = ioutil.WriteFile(backup+compressSuffix, data, 0644)
+	isNil(err, t)
+
+	newFakeTime()
+
+	backup = backupFile(dir)
+	err = ioutil.WriteFile(backup, data, 0644)
+	isNil(err, t)
+
+	// now create a primary log file with some data
+	filename := logFile(dir)
+	err = ioutil.WriteFile(filename, data, 0644)
+	isNil(err, t)
+
+	l := &Logger{
+		Filename:   filename,
+		MaxSize:    10,
+		MaxBackups: 1,
+	}
+	defer l.Close()
+
+	newFakeTime()
+
+	b2 := []byte("foooooo!")
+	n, err := l.Write(b2)
+	isNil(err, t)
+	equals(len(b2), n, t)
+
+	// we need to wait a little bit since the files get deleted on a different
+	// goroutine.
+	<-time.After(time.Millisecond * 10)
+
+	// now we should only have 2 files left - the primary and one backup
+	fileCount(dir, 2, t)
+}
+
+func TestMaxAge(t *testing.T) {
+	currentTime = fakeTime
+	megabyte = 1
+
+	dir := makeTempDir("TestMaxAge", t)
+	defer os.RemoveAll(dir)
+
+	filename := logFile(dir)
+	l := &Logger{
+		Filename: filename,
+		MaxSize:  10,
+		MaxAge:   1,
+	}
+	defer l.Close()
+	b := []byte("boo!")
+	n, err := l.Write(b)
+	isNil(err, t)
+	equals(len(b), n, t)
+
+	existsWithContent(filename, b, t)
+	fileCount(dir, 1, t)
+
+	// two days later
+	newFakeTime()
+
+	b2 := []byte("foooooo!")
+	n, err = l.Write(b2)
+	isNil(err, t)
+	equals(len(b2), n, t)
+	existsWithContent(backupFile(dir), b, t)
+
+	// we need to wait a little bit since the files get deleted on a different
+	// goroutine.
+	<-time.After(10 * time.Millisecond)
+
+	// We should still have 2 log files, since the most recent backup was just
+	// created.
+	fileCount(dir, 2, t)
+
+	existsWithContent(filename, b2, t)
+
+	// we should have deleted the old file due to being too old
+	existsWithContent(backupFile(dir), b, t)
+
+	// two days later
+	newFakeTime()
+
+	b3 := []byte("baaaaar!")
+	n, err = l.Write(b3)
+	isNil(err, t)
+	equals(len(b3), n, t)
+	existsWithContent(backupFile(dir), b2, t)
+
+	// we need to wait a little bit since the files get deleted on a different
+	// goroutine.
+	<-time.After(10 * time.Millisecond)
+
+	// We should have 2 log files - the main log file, and the most recent
+	// backup.  The earlier backup is past the cutoff and should be gone.
+	fileCount(dir, 2, t)
+
+	existsWithContent(filename, b3, t)
+
+	// we should have deleted the old file due to being too old
+	existsWithContent(backupFile(dir), b2, t)
+}
+
+func TestOldLogFiles(t *testing.T) {
+	currentTime = fakeTime
+	megabyte = 1
+
+	dir := makeTempDir("TestOldLogFiles", t)
+	defer os.RemoveAll(dir)
+
+	filename := logFile(dir)
+	data := []byte("data")
+	err := ioutil.WriteFile(filename, data, 07)
+	isNil(err, t)
+
+	// This gives us a time with the same precision as the time we get from the
+	// timestamp in the name.
+	t1, err := time.Parse(backupTimeFormat, fakeTime().UTC().Format(backupTimeFormat))
+	isNil(err, t)
+
+	backup := backupFile(dir)
+	err = ioutil.WriteFile(backup, data, 07)
+	isNil(err, t)
+
+	newFakeTime()
+
+	t2, err := time.Parse(backupTimeFormat, fakeTime().UTC().Format(backupTimeFormat))
+	isNil(err, t)
+
+	backup2 := backupFile(dir)
+	err = ioutil.WriteFile(backup2, data, 07)
+	isNil(err, t)
+
+	l := &Logger{Filename: filename}
+	files, err := l.oldLogFiles()
+	isNil(err, t)
+	equals(2, len(files), t)
+
+	// should be sorted by newest file first, which would be t2
+	equals(t2, files[0].timestamp, t)
+	equals(t1, files[1].timestamp, t)
+}
+
+func TestTimeFromName(t *testing.T) {
+	l := &Logger{Filename: "/var/log/myfoo/foo.log"}
+	prefix, ext := l.prefixAndExt()
+
+	tests := []struct {
+		filename string
+		want     time.Time
+		wantErr  bool
+	}{
+		{"foo-2014-05-04T14-44-33.555.log", time.Date(2014, 5, 4, 14, 44, 33, 555000000, time.UTC), false},
+		{"foo-2014-05-04T14-44-33.555", time.Time{}, true},
+		{"2014-05-04T14-44-33.555.log", time.Time{}, true},
+		{"foo.log", time.Time{}, true},
+	}
+
+	for _, test := range tests {
+		got, err := l.timeFromName(test.filename, prefix, ext)
+		equals(got, test.want, t)
+		equals(err != nil, test.wantErr, t)
+	}
+}
+
+func TestLocalTime(t *testing.T) {
+	currentTime = fakeTime
+	megabyte = 1
+
+	dir := makeTempDir("TestLocalTime", t)
+	defer os.RemoveAll(dir)
+
+	l := &Logger{
+		Filename:  logFile(dir),
+		MaxSize:   10,
+		LocalTime: true,
+	}
+	defer l.Close()
+	b := []byte("boo!")
+	n, err := l.Write(b)
+	isNil(err, t)
+	equals(len(b), n, t)
+
+	b2 := []byte("fooooooo!")
+	n2, err := l.Write(b2)
+	isNil(err, t)
+	equals(len(b2), n2, t)
+
+	existsWithContent(logFile(dir), b2, t)
+	existsWithContent(backupFileLocal(dir), b, t)
+}
+
+func TestRotate(t *testing.T) {
+	currentTime = fakeTime
+	dir := makeTempDir("TestRotate", t)
+	defer os.RemoveAll(dir)
+
+	filename := logFile(dir)
+
+	l := &Logger{
+		Filename:   filename,
+		MaxBackups: 1,
+		MaxSize:    100, // megabytes
+	}
+	defer l.Close()
+	b := []byte("boo!")
+	n, err := l.Write(b)
+	isNil(err, t)
+	equals(len(b), n, t)
+
+	existsWithContent(filename, b, t)
+	fileCount(dir, 1, t)
+
+	newFakeTime()
+
+	err = l.Rotate()
+	isNil(err, t)
+
+	// we need to wait a little bit since the files get deleted on a different
+	// goroutine.
+	<-time.After(10 * time.Millisecond)
+
+	filename2 := backupFile(dir)
+	existsWithContent(filename2, b, t)
+	existsWithContent(filename, []byte{}, t)
+	fileCount(dir, 2, t)
+	newFakeTime()
+
+	err = l.Rotate()
+	isNil(err, t)
+
+	// we need to wait a little bit since the files get deleted on a different
+	// goroutine.
+	<-time.After(10 * time.Millisecond)
+
+	filename3 := backupFile(dir)
+	existsWithContent(filename3, []byte{}, t)
+	existsWithContent(filename, []byte{}, t)
+	fileCount(dir, 2, t)
+
+	b2 := []byte("foooooo!")
+	n, err = l.Write(b2)
+	isNil(err, t)
+	equals(len(b2), n, t)
+
+	// this will use the new fake time
+	existsWithContent(filename, b2, t)
+}
+
+func TestCompressOnRotate(t *testing.T) {
+	currentTime = fakeTime
+	megabyte = 1
+
+	dir := makeTempDir("TestCompressOnRotate", t)
+	defer os.RemoveAll(dir)
+
+	filename := logFile(dir)
+	l := &Logger{
+		Compress: true,
+		Filename: filename,
+		MaxSize:  10,
+	}
+	defer l.Close()
+	b := []byte("boo!")
+	n, err := l.Write(b)
+	isNil(err, t)
+	equals(len(b), n, t)
+
+	existsWithContent(filename, b, t)
+	fileCount(dir, 1, t)
+
+	newFakeTime()
+
+	err = l.Rotate()
+	isNil(err, t)
+
+	// the old logfile should be moved aside and the main logfile should have
+	// nothing in it.
+	existsWithContent(filename, []byte{}, t)
+
+	// we need to wait a little bit since the files get compressed on a different
+	// goroutine.
+	<-time.After(10 * time.Millisecond)
+
+	// a compressed version of the log file should now exist and the original
+	// should have been removed.
+	bc := new(bytes.Buffer)
+	gz := gzip.NewWriter(bc)
+	_, err = gz.Write(b)
+	isNil(err, t)
+	err = gz.Close()
+	isNil(err, t)
+	existsWithContent(backupFile(dir)+compressSuffix, bc.Bytes(), t)
+	notExist(backupFile(dir), t)
+
+	fileCount(dir, 2, t)
+}
+
+func TestCompressOnResume(t *testing.T) {
+	currentTime = fakeTime
+	megabyte = 1
+
+	dir := makeTempDir("TestCompressOnResume", t)
+	defer os.RemoveAll(dir)
+
+	filename := logFile(dir)
+	l := &Logger{
+		Compress: true,
+		Filename: filename,
+		MaxSize:  10,
+	}
+	defer l.Close()
+
+	// Create a backup file and empty "compressed" file.
+	filename2 := backupFile(dir)
+	b := []byte("foo!")
+	err := ioutil.WriteFile(filename2, b, 0644)
+	isNil(err, t)
+	err = ioutil.WriteFile(filename2+compressSuffix, []byte{}, 0644)
+	isNil(err, t)
+
+	newFakeTime()
+
+	b2 := []byte("boo!")
+	n, err := l.Write(b2)
+	isNil(err, t)
+	equals(len(b2), n, t)
+	existsWithContent(filename, b2, t)
+
+	// we need to wait a little bit since the files get compressed on a different
+	// goroutine.
+	<-time.After(10 * time.Millisecond)
+
+	// The write should have started the compression - a compressed version of
+	// the log file should now exist and the original should have been removed.
+	bc := new(bytes.Buffer)
+	gz := gzip.NewWriter(bc)
+	_, err = gz.Write(b)
+	isNil(err, t)
+	err = gz.Close()
+	isNil(err, t)
+	existsWithContent(filename2+compressSuffix, bc.Bytes(), t)
+	notExist(filename2, t)
+
+	fileCount(dir, 2, t)
+}
+
+func TestJson(t *testing.T) {
+	data := []byte(`
+{
+	"filename": "foo",
+	"maxsize": 5,
+	"maxage": 10,
+	"maxbackups": 3,
+	"localtime": true,
+	"compress": true
+}`[1:])
+
+	l := Logger{}
+	err := json.Unmarshal(data, &l)
+	isNil(err, t)
+	equals("foo", l.Filename, t)
+	equals(5, l.MaxSize, t)
+	equals(10, l.MaxAge, t)
+	equals(3, l.MaxBackups, t)
+	equals(true, l.LocalTime, t)
+	equals(true, l.Compress, t)
+}
+
+func TestYaml(t *testing.T) {
+	data := []byte(`
+filename: foo
+maxsize: 5
+maxage: 10
+maxbackups: 3
+localtime: true
+compress: true`[1:])
+
+	l := Logger{}
+	err := yaml.Unmarshal(data, &l)
+	isNil(err, t)
+	equals("foo", l.Filename, t)
+	equals(5, l.MaxSize, t)
+	equals(10, l.MaxAge, t)
+	equals(3, l.MaxBackups, t)
+	equals(true, l.LocalTime, t)
+	equals(true, l.Compress, t)
+}
+
+func TestToml(t *testing.T) {
+	data := `
+filename = "foo"
+maxsize = 5
+maxage = 10
+maxbackups = 3
+localtime = true
+compress = true`[1:]
+
+	l := Logger{}
+	md, err := toml.Decode(data, &l)
+	isNil(err, t)
+	equals("foo", l.Filename, t)
+	equals(5, l.MaxSize, t)
+	equals(10, l.MaxAge, t)
+	equals(3, l.MaxBackups, t)
+	equals(true, l.LocalTime, t)
+	equals(true, l.Compress, t)
+	equals(0, len(md.Undecoded()), t)
+}
+
+// makeTempDir creates a file with a semi-unique name in the OS temp directory.
+// It should be based on the name of the test, to keep parallel tests from
+// colliding, and must be cleaned up after the test is finished.
+func makeTempDir(name string, t testing.TB) string {
+	dir := time.Now().Format(name + backupTimeFormat)
+	dir = filepath.Join(os.TempDir(), dir)
+	isNilUp(os.Mkdir(dir, 0700), t, 1)
+	return dir
+}
+
+// existsWithContent checks that the given file exists and has the correct content.
+func existsWithContent(path string, content []byte, t testing.TB) {
+	info, err := os.Stat(path)
+	isNilUp(err, t, 1)
+	equalsUp(int64(len(content)), info.Size(), t, 1)
+
+	b, err := ioutil.ReadFile(path)
+	isNilUp(err, t, 1)
+	equalsUp(content, b, t, 1)
+}
+
+// logFile returns the log file name in the given directory for the current fake
+// time.
+func logFile(dir string) string {
+	return filepath.Join(dir, "foobar.log")
+}
+
+func backupFile(dir string) string {
+	return filepath.Join(dir, "foobar-"+fakeTime().UTC().Format(backupTimeFormat)+".log")
+}
+
+func backupFileLocal(dir string) string {
+	return filepath.Join(dir, "foobar-"+fakeTime().Format(backupTimeFormat)+".log")
+}
+
+// logFileLocal returns the log file name in the given directory for the current
+// fake time using the local timezone.
+func logFileLocal(dir string) string {
+	return filepath.Join(dir, fakeTime().Format(backupTimeFormat))
+}
+
+// fileCount checks that the number of files in the directory is exp.
+func fileCount(dir string, exp int, t testing.TB) {
+	files, err := ioutil.ReadDir(dir)
+	isNilUp(err, t, 1)
+	// Make sure no other files were created.
+	equalsUp(exp, len(files), t, 1)
+}
+
+// newFakeTime sets the fake "current time" to two days later.
+func newFakeTime() {
+	fakeCurrentTime = fakeCurrentTime.Add(time.Hour * 24 * 2)
+}
+
+func notExist(path string, t testing.TB) {
+	_, err := os.Stat(path)
+	assertUp(os.IsNotExist(err), t, 1, "expected to get os.IsNotExist, but instead got %v", err)
+}
+
+func exists(path string, t testing.TB) {
+	_, err := os.Stat(path)
+	assertUp(err == nil, t, 1, "expected file to exist, but got error from os.Stat: %v", err)
+}
diff --git a/vendor/gopkg.in/natefinch/lumberjack.v2/rotate_test.go b/vendor/gopkg.in/natefinch/lumberjack.v2/rotate_test.go
new file mode 100644
index 0000000..4bd4325
--- /dev/null
+++ b/vendor/gopkg.in/natefinch/lumberjack.v2/rotate_test.go
@@ -0,0 +1,27 @@
+// +build linux
+
+package lumberjack_test
+
+import (
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"gopkg.in/natefinch/lumberjack.v2"
+)
+
+// Example of how to rotate in response to SIGHUP.
+func ExampleLogger_Rotate() {
+	l := &lumberjack.Logger{}
+	log.SetOutput(l)
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, syscall.SIGHUP)
+
+	go func() {
+		for {
+			<-c
+			l.Rotate()
+		}
+	}()
+}
diff --git a/vendor/gopkg.in/natefinch/lumberjack.v2/testing_test.go b/vendor/gopkg.in/natefinch/lumberjack.v2/testing_test.go
new file mode 100644
index 0000000..8e89c08
--- /dev/null
+++ b/vendor/gopkg.in/natefinch/lumberjack.v2/testing_test.go
@@ -0,0 +1,91 @@
+package lumberjack
+
+import (
+	"fmt"
+	"path/filepath"
+	"reflect"
+	"runtime"
+	"testing"
+)
+
+// assert will log the given message if condition is false.
+func assert(condition bool, t testing.TB, msg string, v ...interface{}) {
+	assertUp(condition, t, 1, msg, v...)
+}
+
+// assertUp is like assert, but used inside helper functions, to ensure that
+// the file and line number reported by failures corresponds to one or more
+// levels up the stack.
+func assertUp(condition bool, t testing.TB, caller int, msg string, v ...interface{}) {
+	if !condition {
+		_, file, line, _ := runtime.Caller(caller + 1)
+		v = append([]interface{}{filepath.Base(file), line}, v...)
+		fmt.Printf("%s:%d: "+msg+"\n", v...)
+		t.FailNow()
+	}
+}
+
+// equals tests that the two values are equal according to reflect.DeepEqual.
+func equals(exp, act interface{}, t testing.TB) {
+	equalsUp(exp, act, t, 1)
+}
+
+// equalsUp is like equals, but used inside helper functions, to ensure that the
+// file and line number reported by failures corresponds to one or more levels
+// up the stack.
+func equalsUp(exp, act interface{}, t testing.TB, caller int) {
+	if !reflect.DeepEqual(exp, act) {
+		_, file, line, _ := runtime.Caller(caller + 1)
+		fmt.Printf("%s:%d: exp: %v (%T), got: %v (%T)\n",
+			filepath.Base(file), line, exp, exp, act, act)
+		t.FailNow()
+	}
+}
+
+// isNil reports a failure if the given value is not nil.  Note that values
+// which cannot be nil will always fail this check.
+func isNil(obtained interface{}, t testing.TB) {
+	isNilUp(obtained, t, 1)
+}
+
+// isNilUp is like isNil, but used inside helper functions, to ensure that the
+// file and line number reported by failures corresponds to one or more levels
+// up the stack.
+func isNilUp(obtained interface{}, t testing.TB, caller int) {
+	if !_isNil(obtained) {
+		_, file, line, _ := runtime.Caller(caller + 1)
+		fmt.Printf("%s:%d: expected nil, got: %v\n", filepath.Base(file), line, obtained)
+		t.FailNow()
+	}
+}
+
+// notNil reports a failure if the given value is nil.
+func notNil(obtained interface{}, t testing.TB) {
+	notNilUp(obtained, t, 1)
+}
+
+// notNilUp is like notNil, but used inside helper functions, to ensure that the
+// file and line number reported by failures corresponds to one or more levels
+// up the stack.
+func notNilUp(obtained interface{}, t testing.TB, caller int) {
+	if _isNil(obtained) {
+		_, file, line, _ := runtime.Caller(caller + 1)
+		fmt.Printf("%s:%d: expected non-nil, got: %v\n", filepath.Base(file), line, obtained)
+		t.FailNow()
+	}
+}
+
+// _isNil is a helper function for isNil and notNil, and should not be used
+// directly.
+func _isNil(obtained interface{}) bool {
+	if obtained == nil {
+		return true
+	}
+
+	switch v := reflect.ValueOf(obtained); v.Kind() {
+	case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
+		return v.IsNil()
+	}
+
+	return false
+}
diff --git a/zap/logger.go b/zap/logger.go
new file mode 100644
index 0000000..fa5febe
--- /dev/null
+++ b/zap/logger.go
@@ -0,0 +1,96 @@
+package zap
+
+import (
+	"go.uber.org/zap"
+
+	"go.uber.org/zap/zapcore"
+	"amuz.es/src/infra/logger/rotater"
+)
+
+var (
+	defaultOptions []zap.Option
+	defaultWriter  rotater.RotateSyncer
+	nopCloser      = func() (err error) { return }
+)
+
+func init() {
+	zap.RedirectStdLog(zap.L())
+}
+
+func replaceGlobalLogger(newOne *zap.Logger) {
+	zap.ReplaceGlobals(newOne)
+	zap.RedirectStdLog(newOne)
+}
+
+func Init(
+	verbose bool,
+	formatter *zapcore.Encoder,
+	mainLogName, logFilename, logDir string,
+	maxSizeMb, maxBackup, maxDay int,
+	logLevel zapcore.Level,
+) *zap.SugaredLogger {
+	level := zap.NewAtomicLevelAt(logLevel)
+	defaultWriter = rotater.NewLogWriter(logFilename, maxSizeMb, maxBackup, maxDay, logDir)
+
+	//encoderOption := getEncoderOption(verbose)
+	//formatter := zapcore.NewConsoleEncoder(encoderOption)
+
+	// reset log option slice
+	defaultOptions = getOptions(defaultWriter, verbose)
+
+	log := initLogger(defaultWriter, mainLogName, formatter, level, defaultOptions...)
+
+	replaceGlobalLogger(log)
+	return log.Sugar()
+}
+
+func New(parent *zap.SugaredLogger, moduleName string) *zap.SugaredLogger {
+	if parent == nil {
+		return zap.L().Named(moduleName).Sugar()
+	} else {
+		return parent.Named(moduleName)
+	}
+}
+
+func NewOtherLogger(
+	formatter *zapcore.Encoder,
+	moduleName, logFilename, logDir string,
+	maxSizeMb, maxBackup, maxDay int,
+	logLevel zapcore.Level,
+	fields ...zapcore.Field,
+) (logger *zap.SugaredLogger, closer func() error) {
+	loglevel := zap.NewAtomicLevelAt(logLevel)
+	logWriter := rotater.NewLogWriter(logFilename, maxSizeMb, maxBackup, maxDay, logDir)
+	core := zapcore.NewCore(formatter, logWriter, loglevel)
+
+	if rotateSyncer, ok := logWriter.(rotater.RotateSyncer); ok {
+		closer = rotateSyncer.Close
+	} else {
+		closer = nopCloser
+	}
+
+	options := []zap.Option{zap.ErrorOutput(defaultWriter)}
+	logger = zap.New(core, options...).
+		Named(moduleName).With(fields...).Sugar()
+	return
+}
+
+func initLogger(
+	writer zapcore.WriteSyncer,
+	moduleName string,
+	formatter zapcore.Encoder,
+	level zap.AtomicLevel,
+	options ...zap.Option,
+) *zap.Logger {
+	core := zapcore.NewCore(formatter, writer, level)
+	return zap.New(core, options...).Named(moduleName)
+}
+
+func getOptions(errWriter zapcore.WriteSyncer, verbose bool) (options []zap.Option) {
+	// define  error log
+	options = append(options, zap.ErrorOutput(errWriter))
+	if verbose {
+		options = append(options, zap.AddStacktrace(zap.NewAtomicLevelAt(zap.PanicLevel)))
+	}
+	return
+}
diff --git a/zap/wrapped.go b/zap/wrapped.go
new file mode 100644
index 0000000..8eb5fd5
--- /dev/null
+++ b/zap/wrapped.go
@@ -0,0 +1,15 @@
+package zap
+
+import (
+	"go.uber.org/zap/zapcore"
+	"amuz.es/src/infra/logger/rotater"
+)
+
+type zapWrappedSyncer struct {
+	zapcore.WriteSyncer
+}
+
+func (r *zapWrappedSyncer) SetOnClose(closeFunc rotater.CloseFunc) {}
+func (r *zapWrappedSyncer) Rotate() (err error)                    { return }
+func (r *zapWrappedSyncer) Close() (err error)                     { return }
+func (r *zapWrappedSyncer) Sync() error                            { return r.WriteSyncer.Sync() }