Results class

Hi.  I don't know if you guys are taking pull requests, but I was at PAPis.io conference and was playing a bit with your ruby wrapper. I didn't get a chance to discuss this with you at the conference, but I have added a Results class that exposes a few methods that I found useful rather than having just a simple hash. 

The new functionality is entirely 'opt-in'  (see the ReadMe) and still exposes the []  method so most existing code should work even when opting in.