Merge pull request isotopp#1 from isotopp/dependabot/pip/pyyaml-5.4

Bump pyyaml from 5.3.1 to 5.4

Author: isotopp

requirements-frozen.txt

@@ -13,7 +13,7 @@ mypy-extensions==0.4.3
 nodeenv==1.5.0
 pathspec==0.8.0
 pkg-resources==0.0.0
-PyYAML==5.3.1
+PyYAML==5.4
 regex==2020.7.14
 six==1.15.0
 toml==0.10.1