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_hook.go

@@ -0,0 +1,13 @@
+// Copyright 2015 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
+
+func (repo *Repository) GetHook(name string) (*Hook, error) {
+	return GetHook(repo.Path, name)
+}
+
+func (repo *Repository) Hooks() ([]*Hook, error) {
+	return ListHooks(repo.Path)
+}