Fix tox format.
Fix tox format.

tox is a joke.

harrisonfeng/gunicorn,tempbottle/gunicorn,MrKiven/gunicorn,zhoucen/gunicorn,tejasmanohar/gunicorn,keakon/gunicorn,mvaled/gunicorn,gtrdotmcs/gunicorn,gtrdotmcs/gunicorn,ephes/gunicorn,z-fork/gunicorn,mvaled/gunicorn,mvaled/gunicorn,zhoucen/gunicorn,elelianghh/gunicorn,GitHublong/gunicorn,gtrdotmcs/gunicorn,WSDC-NITWarangal/gunicorn,zhoucen/gunicorn