Log Message:
py-numpy: updated to 1.15.4

NumPy 1.15.4:

This is a bugfix release for bugs and regressions reported following the 1.15.3
release.  The Python versions supported by this release are 2.7, 3.4-3.7. The
wheels are linked with OpenBLAS v0.3.0, which should fix some of the linalg
problems reported for NumPy 1.14.