message: Complete comments for notification settings api
diff: @@ -103,7 +103,14 @@ export class NotificationSettingsController {
  *
  * @apiSuccessExample {json} Success-Response:
  * {
  - * todo
  + * "_id": "5ab283b342949f000857b8f9",
  + * "updatedAt": "2018-03-21T16:09:23.542Z",
  + * "createdAt": "2018-03-21T16:09:23.542Z",
  + * "user": {...},
  + * "course": {...},
  + * "notificationType": "allChanges",
  + * "emailNotification": true,
  + * "__v": 0
  * }
  *
  * @apiError BadRequestError NotificationSettings need course and user
  