Python 3 support

[BradleyKirton]

Given the scope of the package I think implementing Python 3 support should be relatively easy. I am relatively new to contributing to open source and have made a few pull requests to the project already. I would be willing to make the changes to support Python 3.

[CjS77]

With pleasure. I unfortunately don't have time to manage this project any more, so you're more than welcome to submit a PR

[BradleyKirton]

I submitted one over the weekend #12 and ran the test cases for both Python 2.7 and 3.6.