Reciprocalspaceship

What's Changed
* 91 change crystfel parser stddev key to 'SigI'
* minor version updates for dependencies
* 94 Add decorators for gemmi argument checking
* 99 Ensure consistent column ordering in `DataSet.unstack_anomalous()`

**Full Changelog**: https://github.com/Hekstra-Lab/reciprocalspaceship/compare/v0.9.15...v0.9.16

- Update `gemmi` support to 0.4.8
- 86 Standardize code style
- 87, 90 Improve consistency of `DataSet.compute_dHKL()`

- 83 Fix bug in generating reciprocal space ASU

- 76 Add convenience function for removing systematic absences
- Adjust supported pandas version to 1.3.2

- 74 Add support for generators in `rs.concat()`
- 75 Improve numerical stability of angular ewald offset calculation in `rs.read_crystfel()`

- 71 Support Pandas v1.3
- 72 73 Update CrystFEL stream parser to return additional metadata