[NEW PORT] astro/py-pymeeus: Python implementation of Jean Meeus astronomical routines

PyMeeus is a Python implementation of the astronomical algorithms
described in the classical book "Astronomical Algorithms, 2nd Edition,
Willmann-Bell Inc. (1998)" by Jean Meeus.

WWW: https://github.com/architest/pymeeus

MFH: 2019Q3 (required to fix broken py-convertdate)