Update tox to 4.0.8#346

pyup-bot wants to merge 1 commit intomasterwdar/cdippy_2018:masterfrom

pyup-update-tox-3.5.2-to-4.0.8wdar/cdippy_2018:pyup-update-tox-3.5.2-to-4.0.8Copy head branch name to clipboard