Update express.js example for nano 6 and express 4

examples/express.js

@@ -12,16 +12,19 @@
 
 var express = require('express')
    , db    = require('nano')('http://localhost:5984/my_couch')
-   , app     = module.exports = express.createServer()
+   , app     = module.exports = express()
    ;
 
-app.get('/', function(request,response) {
-    db.get('foo', function (error, body, headers) {
-      if(error) { return response.send(error.message, error['status-code']); }
-      response.send(body, 200);
-    });
-  });
+app.get('/', function(req, res) {
+   db.get('foo', function (error, body, headers) {
+      if(error) {
+         res.status(error.statusCode);
+         return res.send(error.message); 
+      }
+      res.status(200);
+      res.send(body);
+   });
 });
 
 app.listen(3333);
-console.log('server is running. check expressjs.org for more cool tricks');
+console.log('server is running. check expressjs.com for more cool tricks');