Add hypothesis library for parametric testing

[tylerriccio33]

Instead of randomly generating numbers using random or the rng from numpy, it would be nice to use the hypothesis package. This package plays nice w/pytest's own parametric features, and it's lightweight. It could make sense to add as a dev dependency; will save some boilerplate. https://github.com/HypothesisWorks/hypothesis

[rich-iannone]

I’m totally up for integration with hypothesis here! If you want to take the lead on this and prepare some PRs, I’ll gladly accept! BTW, you’re the best!

[tylerriccio33]

FYI this would be closed by #94 . Linking it now so we remember to close it when that PR closes.