Add Tests

Adds tests. Increases test coverage from 30% to 70% :smile_cat: 
I introduced this but I'm not convinced that it's best. We *should* be using IntelliJ's code formatter, which gives this as an option, but IntelliJ's code formatter gives *lots* of options, and everyone has different preferences. I'm in favor of coming up with a Toopher Java style guide that we can import into IntelliJ, but I think I'm in the minority.