Create more tests

[akbiggs]

It's starting to get annoying to refactor the scripts because of the amount of manual testing that needs to be done. We should create tests for these scripts (e.g. using the Challonge API to create tournaments, run scripts, verify that the tournament was updated correctly, and then delete the tournament to clean up afterwards).

This will require some refactoring to the scripts to allow test data / mocking to be introduced nicely.

[akbiggs]

I decided to just make the tests verify the script output directly using Bats, started adding stuff under the tests directory.