-r requirements.txt
flake8==3.5.0
pytest==3.7.4
pytest-cov==2.5.1

-r requirements.txt
flake8==3.5.0
pytest==3.7.4
pytest-cov==2.6.0

Update pytest-cov from 2.5.1 to 2.6.0
Update pytest-cov from 2.5.1 to 2.6.0