feat: expose url field on issue api. (#982)

* Add api url func.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

* fix: Add unit testing.

* fix: conflicts

* fix: remove trim

* fix: revert test function name.

models/repo.go

@@ -264,6 +264,11 @@ func (repo *Repository) HTMLURL() string {
 	return setting.AppURL + repo.FullName()
 }
 
+// APIURL returns the repository API URL
+func (repo *Repository) APIURL() string {
+	return setting.AppURL + path.Join("api/v1/repos", repo.FullName())
+}
+
 // APIFormat converts a Repository to api.Repository
 func (repo *Repository) APIFormat(mode AccessMode) *api.Repository {
 	cloneLink := repo.CloneLink()