default_tags specification in setup.cfg doesn't appear to be correct
default_tags in setup.cfg is currently specified as:
default_tags=(not @notimplemented) and (not @nottestable)
I don't believe this is correct. See https://behave.readthedocs.io/en/stable/behave.html#configuration-parameter-types. I believe the correct syntax (from experimentation) is:
default_tags=~@notimplemented
~@nottestable