Add create_at and updated_at in PR json (#1616)

* Move new fields to object creation (use reference)
 * Vendor: Update SDK

models/pull.go

@@ -197,6 +197,8 @@ func (pr *PullRequest) APIFormat() *api.PullRequest {
 		Base:      apiBaseBranchInfo,
 		Head:      apiHeadBranchInfo,
 		MergeBase: pr.MergeBase,
+		Created:   &pr.Issue.Created,
+		Updated:   &pr.Issue.Updated,
 	}
 
 	if pr.Status != PullRequestStatusChecking {