What's Changed
* Store arrow schema when reading catalogs by camposandro in https://github.com/astronomy-commons/hipscat/pull/310
* Clean up unused methods. Prepare for file_system argument. by delucchi-cmu in https://github.com/astronomy-commons/hipscat/pull/315
* Better mypy hints by delucchi-cmu in https://github.com/astronomy-commons/hipscat/pull/316
* Add utility healpix functions to convert between order, average pixel size and minimum distance between edges by hombit in https://github.com/astronomy-commons/hipscat/pull/318
**Full Changelog**: https://github.com/astronomy-commons/hipscat/compare/v0.3.7...v0.3.8