public function push($lat, $long, $user_id)
 {
     $arr = null;
     try {
         $location = new Location();
         $location->latitude = $lat;
         $location->longitude = $long;
         $location->date = Util::dateTimeNow();
         $location->user_id = $user_id;
         $location->save();
         $arr = ['status' => 'OK'];
     } catch (\Exception $e) {
         $arr = ['status' => 'ERROR'];
         Log::error('ERROR: ' . $e->getmessage());
     }
     return json_encode($arr);
 }