refactor: es6 all the things!

routes/index.js

@@ -1,9 +1,9 @@
-var express = require('express');
-var router = express.Router();
+const express = require('express')
+const router = express.Router()
 
 /* GET home page. */
-router.get('/', function(req, res, next) {
-  res.render('index', { title: 'Express' });
-});
+router.get('/', function (req, res, next) {
+  res.render('index', { title: 'Express' })
+})
 
-module.exports = router;
+module.exports = router