build(deps): bump pytest from 5.4.3 to 6.2.1

Bumps [pytest](https://github.com/pytest-dev/pytest) from 5.4.3 to 6.2.1.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@5.4.3...6.2.1)

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

requirements.txt

@@ -16,7 +16,7 @@ bpython
 
 # Testing
 # ----------------------------------------------------------------------------
-pytest==5.4.3
+pytest==6.2.1
 pytest-cookies==0.5.1
 pytest-cov==2.10.1
 pytest-factoryboy==2.0.3