Add repo mirror sync API endpoint (#1508)

* API: Add repo mirror sync

* Correct error message

* Change http status to 200

routers/api/v1/api.go

 						Patch(bind(api.EditReleaseOption{}), repo.EditRelease).
 						Delete(repo.DeleteRelease)
 				})
+				m.Post("/mirror-sync", repo.MirrorSync)
 				m.Get("/editorconfig/:filename", context.RepoRef(), repo.GetEditorconfig)
 				m.Group("/pulls", func() {
 					m.Combo("").Get(bind(api.ListPullRequestsOptions{}), repo.ListPullRequests).Post(reqRepoWriter(), bind(api.CreatePullRequestOption{}), repo.CreatePullRequest)

routers/api/v1/repo/repo.go

 	log.Trace("Repository deleted: %s/%s", owner.Name, repo.Name)
 	ctx.Status(204)
 }
+
+// MirrorSync adds a mirrored repository to the sync queue
+func MirrorSync(ctx *context.APIContext) {
+	repo := ctx.Repo.Repository
+
+	if !ctx.Repo.IsWriter() {
+		ctx.Error(403, "MirrorSync", "Must have write access")
+	}
+
+	go models.MirrorQueue.Add(repo.ID)
+	ctx.Status(200)
+}