Licence?

[weberhofer]

Upon packaging I have seen, that you don't declare a licence for your project. Can you please add a licence file? It would also be great to see the licence in the gemspec as stated here: http://docs.rubygems.org/read/chapter/20#license
Thank you!

[jordimassaguerpla]

Hi! could you please add a license? If you don't know which to choose, I'd advise you to use the MIT license as most of gems do.

[natejenkins]

Any chance we can get a license added here? I would be happy to submit a PR with the MIT license if need be.