v0.1.3: Fix gh-actions (#2)

Library / dependencies update

• Update build system - now supports MacOS (Intel and ARM).
• Cleans up some compiler warnings

Example scripts (after installing with pip install libmcphase)

import libmcphase

cfp = libmcphase.cf1ion('Pr3+', B20=0.1, B40=0.01, B60=0.001, B66=-0.02)
V, E = cfp.eigensystem()
print(E)