Add 'Routes' and 'Express' frameworks to the server

[chenbachar]

Route definition takes the following structure:

app.METHOD(PATH, HANDLER)

Where:

• app is an instance of express.
• METHOD is an HTTP request method.
• PATH is a path on the server.
• HANDLER is the function executed when the route is matched.

The following examples illustrate defining simple routes.
Respond with Hello World! on the homepage:
app.get('/', function (req, res) { res.send('Hello World!'); });

Respond to POST request on the root route (/), the application’s home page:
app.post('/', function (req, res) { res.send('Got a POST request'); });

Respond to a PUT request to the /user route:
app.put('/user', function (req, res) { res.send('Got a PUT request at /user'); });

Respond to a DELETE request to the /user route:
app.delete('/user', function (req, res) { res.send('Got a DELETE request at /user'); });

Reference: http://expressjs.com/en/starter/basic-routing.html