Update tox to 4.20.0#2631

pyup-bot wants to merge 1 commit intomasterkragniz/python-etcd3:masterfrom

pyup-update-tox-3.23.1-to-4.20.0kragniz/python-etcd3:pyup-update-tox-3.23.1-to-4.20.0Copy head branch name to clipboard