with every new addition to this code, we want to make sure it doesn't break. we also want to make sure it makes physical sense. so, we need to add unit tests

• basic test for no bugs
• test for compatibility with gwpop
• code that plots your distribution
• test that results are sensical - not sure what a reasonable way to do this is without depending on data and other physics
• distribution tests:

• draw a bunch of samples
• compute the pdf on a grid
• compute a KS test to make sure they agree
• plot the pdf and a histogram of the samples as proof, include this as part of the docs (sphinx can embed PNGs)

"If we did that for each class in turn, we could build up a rather exhaustive test suite that should protect us and serve as a review. It's a lot of work, though. so we should talk about if/when it makes sense to do this." - Reed