Don't build and ship Python 2 bits on EL > 7 and Fedora > 28
    
    Note that:
    
     - I don't think Python 3 tests were run before at all, hacked it
     - Docs don't build on Python 3, should be brought upstream
     - The if-elsing is ugly sometimes, but I assumed this is
       "one specfile for every Fedora and EL out there" so I went with that