/**
  * User logout
  *
  * @param Request $request
  * @param Response $response
  * @return Response
  */
 public function logout(Request $request = null, Response $response = null)
 {
     $app = $this->app($request);
     $user = new UserSession($app);
     $user->logout($app);
     return $app->http->redirectBase('/login');
 }