Meanstars

Adding a single-source version string in the package init.

This release completely reworks the spectral string parsing functionality in MeanStars, replacing the three separate regular expressions previously used with a single, unified expression that supports a much broader range of valid spectral type strings. In particular, composite classes now have much better support, single decimal points (.) are never treated as valid numbers, and support is added for the rare quarter type (+/- following a subclass).

**Full Changelog**: https://github.com/dsavransky/MeanStars/compare/v3.3.1...v3.4.0

Bugfix release. In v3.3.0, subdwarfs were being assigned a luminosity class of VII. This has been corrected to VI.

New Functionality
- Adding data table lookup function to return row index of nearest match in any well-behaved numerical column.
- Adding standard passband definitions

New Features
- Adding spectral string parsing regular expressions and matching method.
- Adding class attribute with data version string

Internals
- All code is fully type hinted.
- Adding flake8, black and mypy --strict to CI tests.
- CI now run on matrix of python 3.8, 3.9, and 3.10