Add express to project

npm install express to add the express libraries and files
This is going to be an express app, yo.
Add debug_log utility

Add debug_log which will only console.log in DEBUG mode (a bool switch controlled in debug_log.js file)
Place in node_modules so that we don't need to specify a relative path, e.g.
var log = require('debug_log').debug_log;

...
// send to console.log (in DEBUG mode)
log('this message');
Spin up a simple express app

This is just a Hello, World level of app. Doesn't do anything.