Python 3.8

[jayvdb]

unittest-expander has some old code which will likely break on Python 3.8 zuo/unittest_expander#1

http://github.com/maaku/scenariotest/ might be a suitable replacement.

upstream rules checker also has some bad regex EFForg/https-everywhere#18985

[jayvdb]

There is a chunk of code here in _unregex.py:127 that is incompatible with py38

>       new = sre_parse.SubPattern(pattern.pattern)
E       AttributeError: 'SubPattern' object has no attribute 'pattern'