build(deps): bump pyyaml from 5.3.1 to 5.4

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] <[email protected]>

Author: dependabot[bot]

requirements.txt

@@ -74,7 +74,7 @@ pytest-xdist==2.1.0
 python-dateutil==2.8.1
 python-jose==3.2.0
 pytz==2020.1
-PyYAML==5.3.1
+PyYAML==5.4
 regex==2020.7.14
 requests==2.24.0
 responses==0.12.0