Bump pytest from 4.6.2 to 4.6.5 (#136)

Bumps [pytest](https://github.com/pytest-dev/pytest) from 4.6.2 to 4.6.5.
- [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/4.6.2...4.6.5

)

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

requirements.dev.txt

 flake8==3.7.8
 nose==1.3.7
 pylint==1.9.4
-pytest==4.6.2
+pytest==4.6.5
 pytest-watch==4.2.0