scikit-hep/boost-histogram: Version 0.13.0

PlottableProtocol provides a way to plot in different libraries, and easy access to common quantities. This is expected to be the final release for Python 2, and mostly equivalent in API to 1.0.

• Support for PlottableProtocol. You can now access .values(), .counts(), and .variances() on all storages; used by plotting libraries. .kind describes the Kind of the histogram (bh.Kind.COUNT or bh.Kind.MEAN). .options has been renamed to .traits, and a few more useful traits were added, like .discrete. Most other portions of the Protocol were already present. #476
• Removed deprecated .rank on histograms (since 0.8). Use .ndim instead. #505
• Supports converting user histogram objects that provide a _to_boost_histogram_ method. #483
• A view=True parameter must now be passed to get a View instead of a standard NumPy values arrray from to_numpy(). #498

• Added additional support for typing, fixing a couple of rare Python 2 bugs in the process #493.
• The resulting histogram from bh.numpy.* functions is now reducible #508

• Use GitHub Actions for ARM compiling #474
• Apple Silicon support (since 0.12) #495
• Support compiling with C++17 #502
• Rename NPY_NUM_BUILD_JOBS to CMAKE_BUILD_PARALLEL_LEVEL for consistency with other Scikit-HEP projects. #502