Update gunicorn to 25.1.0#200

pyup-bot wants to merge 1 commit intomasterfloatingman/pythontdd:masterfrom

pyup-update-gunicorn-19.8.1-to-25.1.0floatingman/pythontdd:pyup-update-gunicorn-19.8.1-to-25.1.0Copy head branch name to clipboard