Log Message:
py-flake8: updated to 3.7.3

3.7.3:
Bugs Fixed
Fix imports of typing in python 3.5.0 / 3.5.1
Fix flake8 --statistics
Gracefully ignore flake8-per-file-ignores plugin if installed
Improve error message for malformed per-file-ignores

3.7.2:
Bugs Fixed
Fix broken flake8 --diff (regressed in 3.7.0)
Fix typo in plugin exception reporting
Fix AttributeError while attempting to use the legacy api (regressed in
3.7.0)