/**
  * Update the specified appointment in storage.
  *
  * @param  int  $appointment_id
  * @return Response
  *
  */
 public function update($advisor_id, $unavailable_id)
 {
     $event = Unavailable::find($unavailable_id);
     $input = Input::all();
     if (isset($input['start'])) {
         $event->start = Carbon::parse($input['start'])->toDateTimeString();
     }
     if (isset($input['end'])) {
         $event->end = Carbon::parse($input['end'])->toDateTimeString();
     }
     $start = Carbon::parse($event->start);
     $end = Carbon::parse($event->end);
     // Check that start is before end
     if ($start->gt($end)) {
         return Response::json(array('message' => 'Start can not be after end'), 400);
     }
     $event->save();
     return Response::json($event);
 }