Update flake8 from 3.6.0 to 3.7.4
Update flake8 from 3.6.0 to 3.7.4
akatsoulas/mozillians,akatsoulas/mozillians,mozilla/mozillians,akatsoulas/mozillians,mozilla/mozillians,akatsoulas/mozillians,mozilla/mozillians,mozilla/mozillians