Adds pytz as explicit dependency and updates dependency tree

Author: Frank Sachsenheim

poetry.lock

@@ -37,6 +37,7 @@ cerberus = "^1.3.4"
 docker = {version = "^7", extras = ["ssh"]}
 fasteners = "^0.14"
 python-dateutil = "^2.8.1"
+pytz = "*"
 
 [tool.poetry.group.dev.dependencies]
 furo = "*"