Flox

What's Changed
* Many performance optimizations including much better binning by dcherian in https://github.com/dcherian/flox/pull/120
* Propagate attrs better by dcherian in https://github.com/dcherian/flox/pull/124


**Full Changelog**: https://github.com/dcherian/flox/compare/v0.5.8...v0.5.9

What's Changed
* Fix factorizing some more. by dcherian in https://github.com/dcherian/flox/pull/115
* Don't execute hourly climatology notebook by dcherian in https://github.com/dcherian/flox/pull/98
* Allow custom numpy aggregations for "blockwise" by dcherian in https://github.com/dcherian/flox/pull/117


**Full Changelog**: https://github.com/dcherian/flox/compare/v0.5.7...v0.5.8

What's Changed
* Fix bug where we had extra groups in expected_groups. by dcherian, LunarLanding in https://github.com/dcherian/flox/pull/112


**Full Changelog**: https://github.com/dcherian/flox/compare/v0.5.5...v0.5.6

What's Changed
* Convert datetimes to numeric. by dcherian in https://github.com/dcherian/flox/pull/108


**Full Changelog**: https://github.com/dcherian/flox/compare/v0.5.3...v0.5.4