Update flake8 to 3.7.8 (#1855)
Update flake8 to 3.7.8 (#1855)


exercism/xpython,smalley/python,exercism/python,exercism/python,jmluy/xpython,jmluy/xpython,exercism/xpython,behrtam/xpython,smalley/python,behrtam/xpython