Bump pytest from 5.2.1 to 5.2.2 (#75)

Bumps [pytest](https://github.com/pytest-dev/pytest) from 5.2.1 to 5.2.2.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@5.2.1...5.2.2)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

requirements_dev.txt

@@ -1,7 +1,7 @@
 pip==19.3.1
 tox==3.14.0
 coverage==4.5.4
-pytest==5.2.1
+pytest==5.2.2
 
 # Linting & QA
 pre-commit==1.19.0