Convert classes to use Babel syntax

website/src/middlewares/api-v3/index.js

@@ -1,10 +1,9 @@
-'use strict';
-
 // This module is only used to attach middlewares to the express app
 
-let errorHandler = require('./errorHandler');
+import errorHandler from './errorHandler';
+
+export default function middleware (app) {
 
-module.exports = function attachMiddlewares (app) {
   // Error handler middleware, define as the last one
   app.use(errorHandler);
-};
+};