Bump pytz from 2019.3 to 2020.1

Bumps [pytz](https://github.com/stub42/pytz) from 2019.3 to 2020.1.
- [Release notes](https://github.com/stub42/pytz/releases)
- [Commits](stub42/pytz@release_2019.3...release_2020.1)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: jalogisch

requirements.txt

@@ -17,7 +17,7 @@ pathtools==0.1.2
 port-for==0.3.1
 Pygments==2.6.1
 pyparsing==2.4.7
-pytz==2019.3
+pytz==2020.1
 PyYAML==5.3.1
 requests==2.23.0
 singledispatch==3.4.0.3