Merge pull request #30 from blues/dependabot/pip/pyyaml-5.4

Bump pyyaml from 5.3.1 to 5.4

Author: bsatrom

requirements.txt

@@ -2,7 +2,7 @@ future==0.18.2
 iso8601==0.1.12
 pyserial==3.4
 python-periphery==2.0.1
-PyYAML==5.3.1
+PyYAML==5.4
 flake8==3.8.3
 pytest==5.4.3
 pytest-cov==2.8.1