Bump pytest from 4.5.0 to 4.6.1 (#76)

Bumps [pytest](https://github.com/pytest-dev/pytest) from 4.5.0 to 4.6.1.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@4.5.0...4.6.1)

Author: dependabot-preview[bot]

poetry.lock

@@ -43,7 +43,7 @@ flake8-pyi = "^19.2"
 
 safety = "^1.8"
 
-pytest = "^4.5"
+pytest = "^4.6"
 pytest-cov = "^2.7"
 pytest-randomly = "^3.0"