Bump pytest from 4.4.0 to 5.1.1

Bumps [pytest](https://github.com/pytest-dev/pytest) from 4.4.0 to 5.1.1.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@4.4.0...5.1.1)

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

Pipfile

@@ -13,6 +13,6 @@ coveralls = "==1.7.0"
 flake8 = "==3.7.7"
 flake8-docstrings = "==1.3.0"
 flake8-isort = "==2.7.0"
-pytest = "==4.4.0"
+pytest = "==5.1.1"
 pytest-cov = "==2.6.1"
 pytest-selenium = "==1.16.0"