Update to Request-Promise 0.3.1 (untested)

Hi @h0ru5 

Out of curiosity I checked your code to see if you are affected by braking changes when upgrading to Request-Promise 0.3.1.

You may be, depending on how your users use the return value of `runProgram` and `setState`. To be save I added the `.promise()` call to ensure full compatibility. You can find the details in the [migration instructions](https://github.com/tyabonil/request-promise#migrating-from-02x-to-03x).

Unfortunately, I was unable to run your tests. But the JavaScript code generated from your CoffeeScript looks good.

Frohes Schaffen!
Nico