-r requirements.txt
pytest==3.6.1
pytest-cov==2.5.1
wheel==0.31.1
matplotlib==2.2.2

-r requirements.txt
pytest==3.6.1
pytest-cov==2.6.1
wheel==0.31.1
matplotlib==2.2.2

Update pytest-cov from 2.5.1 to 2.6.1
Update pytest-cov from 2.5.1 to 2.6.1