title: "secret" option required for "app.use(express.cookieSession())"
body: <p>The <a href="http://expressjs.com/api.html" rel="nofollow">website</a> does not specify any requirement of 'secret' for using <code>app.use(express.cookieSession());</code> but when using the same in express it calls for 'secret option required. Why?</p>
  
  <p>Even when I provide secret <code>app.use(express.cookieSession({secret: 'abc'}));</code> the following error shows in browser:-</p>
  
  <p><code>TypeError: Cannot read property 'connect.sess' of undefined</code></p>