Update pytest to 5.3.4

[pyup-bot]

This PR updates pytest from 3.2.3 to 5.3.4.

The bot wasn't able to find a changelog for this release. Got an idea?

Links

• PyPI: https://pypi.org/project/pytest
• Homepage: https://docs.pytest.org/en/latest/

[coveralls]

Coverage remained the same at 91.297% when pulling 46a1a8e on pyup-update-pytest-3.2.3-to-5.3.4 into a36cff7 on master.

[coveralls]

Coverage remained the same at 91.297% when pulling 46a1a8e on pyup-update-pytest-3.2.3-to-5.3.4 into a36cff7 on master.

[pyup-bot]

Closing this in favor of #208