Butterpy

This will be the functional version of butterpy going forward. This version was used to create a training set for my work with Kepler Bonus Background light curves, and I will hopefully upload the training set to MAST soon.

butterpy 1.0 is more object-oriented, but in my opinion more legible, and importantly more optimized and thoroughly tested.

Butterpy v0.1.1 is the version used to produce the training set used by [Claytor et al. (2021, in review)](https://ui.adsabs.harvard.edu/abs/2021arXiv210414566C/abstract).