Add tests

[oliviasculley]

This app has no tests 😱 😱 😱
It'd be nice to have some tests 😄

[oliviasculley]

Ideally, the test would also make sure the code passes autopep8's checks, and returns a perfect pylint score 😄

Edit: Actually, I've made another issue for this at #21

[ThorntonMatthewD]

The last item to address for this issue is figuring out how to target and kick off commands in a meaningful and controlled fashion.