Bump pytest from 5.1.0 to 5.1.1

Bumps [pytest](https://github.com/pytest-dev/pytest) from 5.1.0 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@5.1.0...5.1.1)

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

requirements-test.txt

@@ -3,6 +3,6 @@ coverage==4.5.4 # pytest-cov
 mirakuru==2.0.1; python_version>'3.4'
 port-for==0.4
 pymongo==3.9.0
-pytest==5.1.0; python_version>'3.4'
+pytest==5.1.1; python_version>'3.4'
 pytest>=4.4.0; python_version<='3.4' # rq.filter: <5.0.0