Security: PyYAML dependency update

https://nvd.nist.gov/vuln/detail/CVE-2020-1747
https://nvd.nist.gov/vuln/detail/CVE-2020-14343
https://www.cvedetails.com/vulnerability-list/vendor_id-13115/Pyyaml.html

requirments.txt

@@ -65,7 +65,7 @@ python-dateutil==2.8.1
 pytz==2020.4
 pyudev==0.22.0
 pyxattr==0.7.1
-PyYAML==5.3.1
+PyYAML==5.4.1
 requests==2.24.0
 requests-file==1.5.1
 requests-oauthlib==1.3.0
@@ -81,4 +81,4 @@ uritemplate==3.0.1
 urllib3==1.25.11
 validators==0.18.1
 wcwidth==0.2.5
-websocket-client==0.57.0
+websocket-client==0.57.0