go:
	./fs some input
	# pycodestyle==2.3.1
	# pydocstyle==2.1.1
	# pyflakes==1.6.0
	/usr/local/bin/pycodestyle fs
	/usr/local/bin/pydocstyle fs
	# pyflakes 1.6.0 is a problem
	/usr/local/bin/pyflakes fs