Move to new build system

[EdGrrr]

The numpy distutils build system is no longer supported. You can get the module to build if using setuptools <60, but this will eventually not work with up-to-date versions of python.

Options are:
cmake/scikit-build - https://scikit-build.readthedocs.io/en/latest/index.html
meson - https://mesonbuild.com/

I am leaning towards cmake for now