Update import paths from github.com/go-gitea to code.gitea.io (#135)

- Update import paths from github.com/go-gitea to code.gitea.io
- Fix import path for travis

See https://docs.travis-ci.com/user/languages/go#Go-Import-Path

vendor/code.gitea.io/git/repo_object.go

@@ -0,0 +1,14 @@
+// Copyright 2014 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+type ObjectType string
+
+const (
+	OBJECT_COMMIT ObjectType = "commit"
+	OBJECT_TREE   ObjectType = "tree"
+	OBJECT_BLOB   ObjectType = "blob"
+	OBJECT_TAG    ObjectType = "tag"
+)