v0.8.8

• Add utility method for computing phase restrictions
• Bug fixes to improve handling of the MultiIndex in DataSet built-in methods (#6)
• Add append/concat methods to DataSet and rs that preserve metadata/attributes
• Argument to account for centering in epsilon calculation (#7)
• Improve performance of hkl_is_absent() and is_centric() through calls to gemmi vectorized functions
• Add methods for binning reflections (e.g. by resolution: #9)
• Most importantly: rs now has a logo... 1/:rocket: