Bump pytest from 5.3.2 to 5.3.4 (#189)

Bumps [pytest](https://github.com/pytest-dev/pytest) from 5.3.2 to 5.3.4.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/pytest-dev/pytest/compare/5.3.2...5.3.4

)

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

requirements.dev.txt

@@ -3,5 +3,5 @@
 pylint==2.4.4
 flake8==3.7.9
 nose==1.3.7
-pytest==5.3.2
+pytest==5.3.4
 pytest-watch==4.2.0