mypy: Added Dict, List and Set imports.

Fixed mypy errors associated with the upgrade.

integrations/openshift/post_deploy

@@ -25,6 +25,7 @@
 import os
 import subprocess
 import sys
+from typing import Dict
 
 sys.path.insert(0, os.path.dirname(__file__))
 import zulip_openshift_config as config

integrations/openshift/zulip_openshift_config.py

@@ -21,7 +21,7 @@
 # THE SOFTWARE.
 
 # https://github.com/python/mypy/issues/1141
-from typing import Text
+from typing import Dict, Text
 
 # Change these values to configure authentication for the plugin
 ZULIP_USER = 'openshift-bot@example.com'