Integrate testing

Hey Melvin,

what we did is we added a lot of rails specific stuff to being able to run the tests. Then we fixed the tests where they failed and added a new one. Additonally we cleaned up the gemspec and removed the jeweler stuff.
I rebased your changes into this feature branche so it should be really easy to merge this into your master.
We will be adding more tests over the time. 

Keep up the great work.

With best regards,
Moritz