Try fixing 'Multiple top-level packages discovered in a flat-layout' …

…error

npy_argparse: fix thread-safety issue when initializing argument cache

nogil: make multiarray buffer protocol implementation thread-safe

nogil: disable cache

NumPy 1.19.0 release

NumPy 1.19.0rc2 release.

NumPy 1.19.0rc1 release

NumPy 1.18.4 release

NumPy 1.18.3 release.

NumPy 1.18.2 release