Performance improvements
What's Changed
* Fix versioneer configuration. by sebastic in https://github.com/ml31415/numpy-groupies/pull/71
* Fix pytest failure without numba. by sebastic in https://github.com/ml31415/numpy-groupies/pull/72
* Move to micromamba by dcherian in https://github.com/ml31415/numpy-groupies/pull/76
* Use faster group_idx creation when axis == -1 by dcherian in https://github.com/ml31415/numpy-groupies/pull/77
* Some optimizations for numpy aggregations by dcherian in https://github.com/ml31415/numpy-groupies/pull/78
New Contributors
* sebastic made their first contribution in https://github.com/ml31415/numpy-groupies/pull/71
**Full Changelog**: https://github.com/ml31415/numpy-groupies/compare/v0.9.20...v0.9.21