Updated flow.js node backend example.

[Partyschaum]

• Modified the response settings accordingly to the actual express version
• The "Access-Control-Allow-Origin" headers are easily configurable now.

[AidasK]

What about these?
https://github.com/Partyschaum/flow.js/blob/fix-node-example-app/samples/Node.js/app.js#L24
https://github.com/Partyschaum/flow.js/blob/fix-node-example-app/samples/Node.js/app.js#L42

This is just an example, to make it simple, cross origin request support is commented out.

[Partyschaum]

Sorry, seems I was to early with my PR. 😓

This is just an example, to make it simple, cross origin request support is commented out.

I know, but I also modified the express related response settings since the (example) app threw some deprecation warnings.