Update Express required version to mitigate GitHub security notice - other location.

Author: geerlingguy

nodejs/provisioning/app/app.js

@@ -2,8 +2,8 @@
 // @see http://howtonode.org/getting-started-with-express
 
 // Load the express module.
-var express = require('express'),
-app = express.createServer();
+var express = require('express');
+var app = express();
 
 // Respond to requests for / with 'Hello World'.
 app.get('/', function(req, res){

nodejs/provisioning/app/package.json

@@ -3,7 +3,7 @@
   "description": "Example Express Node.js app.",
   "author": "Jeff Geerling <[email protected]>",
   "dependencies": {
-    "express": "3.x.x"
+    "express": "4.x"
   },
   "engine": "node >= 0.10.6"
 }