Flake8-bugbear

* add B026: find argument unpacking after keyword argument (287)
* Move to setup.cfg like flake8 (288)

* Add B025: Find duplicate except clauses (284)

* Add B024 error code to message for B024 (276)

* Add B024: abstract base class with no abstract methods (273)

* Implement late-binding loop check (265)
* [late-binding closures are a classic gotcha](https://docs.python-guide.org/writing/gotchas/#late-binding-closures>).

* Don't crash when select / extend_select are None (261)
* Unlocks new flake8 release - Thanks asottile
* Ignore lambda arguments for B020 (259)
* Fix missing space typos in B021, B022 error messages (257)