Catch exception attempting to create an archived channel

Author: Chris O'Dell

response/slack/client.py

@@ -143,8 +143,8 @@ def get_usergroup_users(self, group_id):
         return None
 
     def create_channel(self, name):
-        response = self.api_call("channels.create", name=name)
         try:
+            response = self.api_call("channels.create", name=name)
             return response["channel"]["id"]
         except KeyError:
             raise SlackError(