E711 / E712 checks test for None != arg and False == arg

(Fixes #307)

I also addressed a similar issue for E712 so it also checks for `if False == arg` and so on - seemed to make sense and it would have been harder not to.
Shouldn't this be `same = (match.group('op') == '==')`? You're still capturing the string, but you're not determining if the comparison was for it to be the same as the singleton or not.