-r requirements.txt

pytest==4.2.0
pytest-cov==2.6.1
pytest-mock==1.10.1
codecov==2.0.15
coverage==4.5.2
flake8==3.7.5
black==18.9b0

-r requirements.txt

pytest==4.3.1
pytest-cov==2.6.1
pytest-mock==1.10.1
codecov==2.0.15
coverage==4.5.2
flake8==3.7.5
black==18.9b0

Update pytest from 4.2.0 to 4.3.1
Update pytest from 4.2.0 to 4.3.1