-r requirements.txt
-r requirements-optional.txt
tox==3.8.6
pytest==4.5.0
coverage==4.5.3

-r requirements.txt
-r requirements-optional.txt
tox==3.11.1
pytest==4.5.0
coverage==4.5.3

Update tox from 3.8.6 to 3.11.1
Update tox from 3.8.6 to 3.11.1