jax

b2fe46f3 - Rename MacOS build script to be more consistent with Linux build script.

Rename MacOS build script to be more consistent with Linux build script. Pin particular versions of Numpy and Scipy in the build script to fix Numpy extension version compatibility issue. If jaxlib is built against numpy 1.16 but used against an older version, we see an error "No module named 'numpy.core._multiarray_umath'". The fix is to build against numpy 1.15.