ch04s09 Add build-app project for lab

build-app/app.js

@@ -0,0 +1,11 @@
+var express = require('express');
+app = express();
+
+app.get('/', function (req, res) {
+  res.send('Simple app for the Building Applications Lab!\n');
+});
+
+app.listen(8080, function () {
+  console.log('Simple app for the Building Applications Lab!');
+});
+