/**
  * @author Carl Dalid
  * @description Check if FB ID exist, if true update GCM Token
  */
 public function getUpdateGcmToken($fb_id, $gcm)
 {
     $user = User::checkFBUser($fb_id);
     if ($user) {
         User::updateGCMToken($fb_id, $gcm);
         return json_encode(['success' => 1, 'user' => $user]);
     } else {
         return json_encode(['success' => 0]);
     }
 }