/**
  * Request user input
  * create passenger
  * save belongsto relationship with Booking model.
  *
  * @param $request [request all user input]
  * @param $id      [get booking id]
  */
 public function addBookingDetail($request, $id)
 {
     $booking = $this->booking->getById($id);
     $givenInput = $request->all();
     $data = $this->model->create($givenInput);
     $booking->passenger()->save($data);
 }