Add tests and test runner

[jaywon]

I haven't written tests in Python before so I'm open to suggestion on test suite/runner.

[dchan3]

Hello Jason,

There is a Python module made for unit testing called unittest. I hope this helps!

[jaywon]

Thanks @dchan3! Yes that's helpful, hopefully I can get a chance to work on this again soon ⌛️

[dchan3]

Thinking about it now, I began using Travis for testing my code a while ago, and personally I think it might be a good option as well. It will automatically run specified tests when users submit pull requests.

[jaywon]

Travis is great, CircleCI is another great tool. We just need tests to run 😆