Define auth error

src/controllers/auth.js

@@ -5,6 +5,17 @@ import config from '../../config'
 
 const router = new Router({ prefix: '/auth' })
 
+/**
+ * @apiDefine TokenError
+ * @apiError Unauthorized Invalid JWT token
+ *
+ * @apiErrorExample {json} Error-Response:
+ *     HTTP/1.1 401 Unauthorized
+ *     {
+ *       "status": 401,
+ *       "error": "Unauthorized"
+ *     }
+ */
 
 /**
  * @api {post} /auth Authenticate user