[pkg] Configure "universal" wheel build According to https://packaging.python.org/distributing/#wheels, we should create universal wheels (no 2to3 step, no C extension). Configure this in setup.cfg. [ci skip]

version=3
opts=uversionmangle=s/(rc|a|b|c)/~$1/ \
https://pypi.debian.net/cubicweb/cubicweb-(.+)\.(?:zip|tgz|tbz|txz|(?:tar\.(?:gz|bz2|xz)))