lint: ignore .venv for flake8 for local virtualenv

setup.cfg

@@ -8,7 +8,7 @@ selenium_driver = chrome
 [flake8]
 ignore = F999,E501,E128,E124,E402,W503,E731,C901
 max-line-length = 100
-exclude = .git,*/south_migrations/*,node_modules/*,src/sentry/static/sentry/vendor/*,docs/*,src/south/*,examples/*
+exclude = .venv/.git,*/south_migrations/*,node_modules/*,src/sentry/static/sentry/vendor/*,docs/*,src/south/*,examples/*
 
 [bdist_wheel]
 python-tag = py27