Merge #29

29: Update pytest to 3.7.3 r=rehandalal a=pyup-bot


This PR updates [pytest](https://pypi.org/project/pytest) from **3.7.2** to **3.7.3**.



*The bot wasn't able to find a changelog for this release. [Got an idea?](https://github.com/pyupio/changelogs/issues/new)*

<details>
  <summary>Links</summary>
  
  - PyPI: https://pypi.org/project/pytest
  - Changelog: https://pyup.io/changelogs/pytest/
  - Homepage: http://pytest.org
</details>



Co-authored-by: pyup-bot <[email protected]>

requirements-dev.txt

@@ -1,4 +1,4 @@
 -r requirements.txt
 flake8==3.5.0
-pytest==3.7.2
+pytest==3.7.3
 pytest-cov==2.5.1