5.0.13

Added knowledge of Python versions 3.6.15 and 3.7.12.

However the main motivation was to impove packaging to handle administration
of the 3 different branches or dialects of Python 2.4-2.7, 3.1-3.2, 3.3-3.5, and 3.6+

Restrict wheel packaging for Python 3 only.

Use the wheel for only the 3.x and newer version of Python.
Use eggs for 2.x versions (and others as well).