Use gopkg provider instead of github

With gopkg we can use versioning
otherwise the github link will
always point to the master branch

app/controllers/comment.go

@@ -19,9 +19,9 @@ package controllers
 
 import (
   "github.com/revel/revel"
-  "github.com/ganggo/ganggo/app/models"
-  "github.com/ganggo/ganggo/app/jobs"
-  "github.com/ganggo/federation"
+  "gopkg.in/ganggo/ganggo.v0/app/models"
+  "gopkg.in/ganggo/ganggo.v0/app/jobs"
+  federation "gopkg.in/ganggo/federation.v0"
 )
 
 type ApiComment struct {

app/controllers/like.go

@@ -20,7 +20,7 @@ package controllers
 import (
   "net/http"
   "github.com/revel/revel"
-  "github.com/ganggo/ganggo/app/models"
+  "gopkg.in/ganggo/ganggo.v0/app/models"
 )
 
 type ApiLike struct {

app/controllers/people.go

@@ -19,7 +19,7 @@ package controllers
 
 import (
   "github.com/revel/revel"
-  "github.com/ganggo/ganggo/app/models"
+  "gopkg.in/ganggo/ganggo.v0/app/models"
 )
 
 type ApiPeople struct {

app/controllers/post.go

@@ -19,9 +19,9 @@ package controllers
 
 import (
   "github.com/revel/revel"
-  "github.com/ganggo/ganggo/app/models"
-  "github.com/ganggo/ganggo/app/jobs"
-  "github.com/ganggo/federation"
+  "gopkg.in/ganggo/ganggo.v0/app/models"
+  "gopkg.in/ganggo/ganggo.v0/app/jobs"
+  federation "gopkg.in/ganggo/federation.v0"
 )
 
 type ApiPost struct {

app/controllers/profile.go

@@ -19,7 +19,7 @@ package controllers
 
 import (
   "github.com/revel/revel"
-  "github.com/ganggo/ganggo/app/models"
+  "gopkg.in/ganggo/ganggo.v0/app/models"
 )
 
 type ApiProfile struct {