Bump pyyaml from 5.3.1 to 5.4 (#10)

Bumps [pyyaml](https://github.com/yaml/pyyaml) from 5.3.1 to 5.4.
- [Release notes](https://github.com/yaml/pyyaml/releases)
- [Changelog](https://github.com/yaml/pyyaml/blob/master/CHANGES)
- [Commits](yaml/pyyaml@5.3.1...5.4)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements.txt

@@ -51,7 +51,7 @@ pytest==6.2.1
 pytest-cov==2.10.1
 python-dateutil==2.8.1
 pytz==2020.5
-PyYAML==5.3.1
+PyYAML==5.4
 regex==2020.11.13
 repoze.lru==0.7
 requests==2.25.1