-r requirements.txt
flake8==3.5.0
pytest==3.6.4
pytest-cov==2.5.1
pytest-runner==4.2
tox==3.0.0

-r requirements.txt
flake8==3.5.0
pytest==3.6.4
pytest-cov==2.5.1
pytest-runner==4.2
tox==3.1.2

Update tox from 3.0.0 to 3.1.2
Update tox from 3.0.0 to 3.1.2