Use dep for dependencies

Make setup and predictable builds easier for contributors by locking to
a set of dependencies. Some of the dependencies have been locked to
specific commits on master in order to accomodate projects that do not
ship releases often such as cobra and gomock (see
spf13/cobra#259 for details).

- Change mockgen commands to use a -source flag to explicitly point to
  the files in vendor for generating mocks. This, for some reason, fixes
  a bug in gomock whereby it uses the vendor path as the import path
  which breaks some dependencies.

  See golang/mock#28 for more details.

.gitignore

@@ -2,3 +2,4 @@
 bin
 fargate
 dist
+vendor

Gopkg.toml

@@ -0,0 +1,54 @@
+
+# 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 = "github.com/aws/aws-sdk-go"
+  version = "1.12.70"
+
+[[constraint]]
+  name = "github.com/golang/mock"
+  revision = "b3e60bcdc577185fce3cf625fc96b62857ce5574"
+
+[[constraint]]
+  branch = "master"
+  name = "github.com/hashicorp/golang-lru"
+
+[[constraint]]
+  name = "github.com/kyokomi/emoji"
+  version = "1.5.0"
+
+[[constraint]]
+  branch = "master"
+  name = "github.com/mgutz/ansi"
+
+[[constraint]]
+  name = "github.com/spf13/cobra"
+  revision = "ccaecb155a2177302cb56cae929251a256d0f646"
+
+[[constraint]]
+  branch = "master"
+  name = "golang.org/x/crypto"
+
+[[constraint]]
+  branch = "master"
+  name = "golang.org/x/time"

acm/main.go

@@ -1,7 +1,7 @@
 package acm
 
 //go:generate mockgen -package client -destination=mock/client/client.go github.com/jpignata/fargate/acm Client
-//go:generate mockgen -package sdk -destination=mock/sdk/acmiface.go github.com/aws/aws-sdk-go/service/acm/acmiface ACMAPI
+//go:generate mockgen -package sdk -source ../vendor/github.com/aws/aws-sdk-go/service/acm/acmiface/interface.go -destination=mock/sdk/acmiface.go github.com/aws/aws-sdk-go/service/acm/acmiface ACMAPI
 
 import (
 	"github.com/aws/aws-sdk-go/aws/session"