v3.0.0rc2

I know I said there wouldn't be another rc version but this one does quite a bit of useful stuff, so thought there should be.

Fixes

• Fixed a bug (yes, totally a bug) where the AsyncAnalytics class couldn't retrieve reports

Changes

• Changed all data constants to be sets natively so they don't have to be converted to sets every single request

Beyond that, it's just adding docs and stuff. Playlists and 100% test coverage needs to be done before stable v3.0.0 releases, but shouldn't be too long, in theory.