Bump pyyaml from 5.2 to 5.4

Bumps [pyyaml](https://github.com/yaml/pyyaml) from 5.2 to 5.4.
- [Release notes](https://github.com/yaml/pyyaml/releases)
- [Changelog](https://github.com/yaml/pyyaml/blob/master/CHANGES)
- [Commits](yaml/pyyaml@5.2...5.4)

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

requirements-dev.txt

@@ -33,7 +33,7 @@ pytest==5.3.2
 pytest-antilru==1.0.5
 pytest-sugar==0.9.2
 pytest-watch==4.2.0
-PyYAML==5.2
+PyYAML==5.4
 requirements-tools==1.2.1
 responses==0.10.9
 six==1.13.0