Update go dep (#1560)

This fix updates go dep with `dep ensure --update` as well as the following:
- Removed github.com/ugorji/go restriction in Gopkg.toml (fixes  #1557)
- Added github.com/flynn/go-shlex in Makefile (neede by Caddy, maybe removed later)

This fix fixes #1557

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

vendor/github.com/imdario/mergo/.travis.yml

@@ -1,2 +1,7 @@
 language: go
-install: go get -t
+install:
+  - go get -t
+  - go get golang.org/x/tools/cmd/cover
+  - go get github.com/mattn/goveralls
+script:
+  - $HOME/gopath/bin/goveralls -service=travis-ci -repotoken $COVERALLS_TOKEN

vendor/github.com/imdario/mergo/README.md

@@ -2,17 +2,16 @@
 
 A helper to merge structs and maps in Golang. Useful for configuration default values, avoiding messy if-statements.
 
-Also a lovely [comune](http://en.wikipedia.org/wiki/Mergo) (municipality) in the Province of Ancona in the Italian region Marche.
-
-![Mergo dall'alto](http://www.comune.mergo.an.it/Siti/Mergo/Immagini/Foto/mergo_dall_alto.jpg)
+Also a lovely [comune](http://en.wikipedia.org/wiki/Mergo) (municipality) in the Province of Ancona in the Italian region of Marche.
 
 ## Status
 
-It is ready for production use. It works fine after extensive use in the wild.
+It is ready for production use. [It is used in several projects by Docker, Google, The Linux Foundation, VMWare, Shopify, etc](https://github.com/imdario/mergo#mergo-in-the-wild).
 
 [![Build Status][1]][2]
 [![GoDoc][3]][4]
 [![GoCard][5]][6]
+[![Coverage Status][7]][8]
 
 [1]: https://travis-ci.org/imdario/mergo.png
 [2]: https://travis-ci.org/imdario/mergo
@@ -20,19 +19,41 @@ It is ready for production use. It works fine after extensive use in the wild.
 [4]: https://godoc.org/github.com/imdario/mergo
 [5]: https://goreportcard.com/badge/imdario/mergo
 [6]: https://goreportcard.com/report/github.com/imdario/mergo
+[7]: https://coveralls.io/repos/github/imdario/mergo/badge.svg?branch=master
+[8]: https://coveralls.io/github/imdario/mergo?branch=master
+
+### Latest release
+
+[Release 0.3.1](https://github.com/imdario/mergo/releases/tag/0.3.1) is an important release because it changes `Merge()`and `Map()` signatures to support [transformers](#transformers). An optional/variadic argument has been added, so it won't break existing code.
 
 ### Important note
 
-Mergo is intended to assign **only** zero value fields on destination with source value. Since April 6th it works like this. Before it didn't work properly, causing some random overwrites. After some issues and PRs I found it didn't merge as I designed it. Thanks to [imdario/mergo#8](https://github.com/imdario/mergo/pull/8) overwriting functions were added and the wrong behavior was clearly detected.
-
 If you were using Mergo **before** April 6th 2015, please check your project works as intended after updating your local copy with ```go get -u github.com/imdario/mergo```. I apologize for any issue caused by its previous behavior and any future bug that Mergo could cause (I hope it won't!) in existing projects after the change (release 0.2.0).
 
 ### Mergo in the wild
 
-- [docker/docker](https://github.com/docker/docker/)
+- [moby/moby](https://github.com/moby/moby)
 - [kubernetes/kubernetes](https://github.com/kubernetes/kubernetes)
+- [vmware/dispatch](https://github.com/vmware/dispatch)
+- [Shopify/themekit](https://github.com/Shopify/themekit)
 - [imdario/zas](https://github.com/imdario/zas)
+- [matcornic/hermes](https://github.com/matcornic/hermes)
+- [OpenBazaar/openbazaar-go](https://github.com/OpenBazaar/openbazaar-go)
+- [kataras/iris](https://github.com/kataras/iris)
+- [michaelsauter/crane](https://github.com/michaelsauter/crane)
+- [go-task/task](https://github.com/go-task/task)
+- [sensu/uchiwa](https://github.com/sensu/uchiwa)
+- [ory/hydra](https://github.com/ory/hydra)
+- [sisatech/vcli](https://github.com/sisatech/vcli)
+- [dairycart/dairycart](https://github.com/dairycart/dairycart)
+- [projectcalico/felix](https://github.com/projectcalico/felix)
+- [resin-os/balena](https://github.com/resin-os/balena)
+- [go-kivik/kivik](https://github.com/go-kivik/kivik)
+- [Telefonica/govice](https://github.com/Telefonica/govice)
+- [supergiant/supergiant](supergiant/supergiant)
+- [SergeyTsalkov/brooce](https://github.com/SergeyTsalkov/brooce)
 - [soniah/dnsmadeeasy](https://github.com/soniah/dnsmadeeasy)
+- [ohsu-comp-bio/funnel](https://github.com/ohsu-comp-bio/funnel)
 - [EagerIO/Stout](https://github.com/EagerIO/Stout)
 - [lynndylanhurley/defsynth-api](https://github.com/lynndylanhurley/defsynth-api)
 - [russross/canvasassignments](https://github.com/russross/canvasassignments)
@@ -50,7 +71,7 @@ If you were using Mergo **before** April 6th 2015, please check your project wor
 - [thoas/picfit](https://github.com/thoas/picfit)
 - [mantasmatelis/whooplist-server](https://github.com/mantasmatelis/whooplist-server)
 - [jnuthong/item_search](https://github.com/jnuthong/item_search)
-- [Iris Web Framework](https://github.com/kataras/iris)
+- [bukalapak/snowboard](https://github.com/bukalapak/snowboard)
 
 ## Installation
 
@@ -71,7 +92,7 @@ if err := mergo.Merge(&dst, src); err != nil {
 }
 ```
 
-Also, you can merge overwriting values using the transformer WithOverride.
+Also, you can merge overwriting values using the transformer `WithOverride`.
 
 ```go
 if err := mergo.Merge(&dst, src, WithOverride); err != nil {
@@ -79,7 +100,7 @@ if err := mergo.Merge(&dst, src, WithOverride); err != nil {
 }
 ```
 
-Additionally, you can map a map[string]interface{} to a struct (and otherwise, from struct to map), following the same restrictions as in Merge(). Keys are capitalized to find each corresponding exported field.
+Additionally, you can map a `map[string]interface{}` to a struct (and otherwise, from struct to map), following the same restrictions as in `Merge()`. Keys are capitalized to find each corresponding exported field.
 
 ```go
 if err := mergo.Map(&dst, srcMap); err != nil {
@@ -151,6 +172,7 @@ func (t timeTransfomer) Transformer(typ reflect.Type) func(dst, src reflect.Valu
 					dst.Set(src)
 				}
 			}
+			return nil
 		}
 	}
 	return nil

vendor/github.com/imdario/mergo/issue33_test.go

@@ -28,6 +28,6 @@ func TestIssue33Merge(t *testing.T) {
 		t.Errorf("Error while merging: %s", err)
 	}
 	if dest.Str != toMerge.Str {
-		t.Errorf("dest.Str should have been override: dest.Str(%v) == toMerge.Str(%v)", dest.Str, toMerge.Str)
+		t.Errorf("dest.Str should have been override: dest.Str(%v) != toMerge.Str(%v)", dest.Str, toMerge.Str)
 	}
 }

vendor/github.com/imdario/mergo/merge.go

@@ -54,7 +54,7 @@ func deepMerge(dst, src reflect.Value, visited map[uintptr]*visit, depth int, co
 		visited[h] = &visit{addr, typ, seen}
 	}
 
-	if config.transformers != nil {
+	if config.transformers != nil && !isEmptyValue(dst) {
 		if fn := config.transformers.Transformer(dst.Type()); fn != nil {
 			err = fn(dst, src)
 			return

vendor/github.com/imdario/mergo/merge_test.go

@@ -0,0 +1,50 @@
+package mergo
+
+import (
+	"reflect"
+	"testing"
+)
+
+type transformer struct {
+	m map[reflect.Type]func(dst, src reflect.Value) error
+}
+
+func (s *transformer) Transformer(t reflect.Type) func(dst, src reflect.Value) error {
+	if fn, ok := s.m[t]; ok {
+		return fn
+	}
+	return nil
+}
+
+type foo struct {
+	s   string
+	Bar *bar
+}
+
+type bar struct {
+	i int
+	s map[string]string
+}
+
+func TestMergeWithTransformerNilStruct(t *testing.T) {
+	a := foo{s: "foo"}
+	b := foo{Bar: &bar{i: 2, s: map[string]string{"foo": "bar"}}}
+	if err := Merge(&a, &b, WithOverride, WithTransformers(&transformer{
+		m: map[reflect.Type]func(dst, src reflect.Value) error{
+			reflect.TypeOf(&bar{}): func(dst, src reflect.Value) error {
+				// Do sthg with Elem
+				t.Log(dst.Elem().FieldByName("i"))
+				t.Log(src.Elem())
+				return nil
+			},
+		},
+	})); err != nil {
+		t.Fatal(err)
+	}
+	if a.s != "foo" {
+		t.Fatalf("b not merged in properly: a.s.Value(%s) != expected(%s)", a.s, "foo")
+	}
+	if a.Bar == nil {
+		t.Fatalf("b not merged in properly: a.Bar shouldn't be nil")
+	}
+}

vendor/github.com/imdario/mergo/mergo.go

@@ -47,6 +47,8 @@ func isEmptyValue(v reflect.Value) bool {
 		return v.Float() == 0
 	case reflect.Interface, reflect.Ptr, reflect.Func:
 		return v.IsNil()
+	case reflect.Invalid:
+		return true
 	}
 	return false
 }