Update tox to 4.21.0#730

pyup-bot wants to merge 1 commit intomasterdchaplinsky/aiohttp_validate:masterfrom

pyup-update-tox-3.13.2-to-4.21.0dchaplinsky/aiohttp_validate:pyup-update-tox-3.13.2-to-4.21.0Copy head branch name to clipboard