public function addAction(Request $request, Application $app)
 {
     if (!$request->request->has('name')) {
         return $app->json('Missing required parameter: name', 400);
     }
     if (!$request->request->has('short_biography')) {
         return $app->json('Missing required parameter: short_biography', 400);
     }
     $user = new User();
     $user->setName($request->request->get('name'));
     $user->setShortBiography($request->request->get('short_biography'));
     $user->setBiography($request->request->get('biography'));
     $user->setSoundCloudUrl($request->request->get('soundcloud_url'));
     $app['repository.user']->save($user);
     $headers = array('Location' => '/api/user/' . $user->getId());
     return $app->json('Created', 201, $headers);
 }