Update pyflakes to 2.3.1#23

pyup-bot wants to merge 1 commit intomasterSuperFeliz/libpythonpro:masterfrom

pyup-update-pyflakes-2.1.1-to-2.3.1SuperFeliz/libpythonpro:pyup-update-pyflakes-2.1.1-to-2.3.1Copy head branch name to clipboard