clean up unnecessary usage of the six library (awx only supports py3)

awx/settings/defaults.py

@@ -4,7 +4,6 @@
 import os
 import re  # noqa
 import sys
-import six
 from datetime import timedelta
 
 # global settings
@@ -499,11 +498,11 @@ CELERYBEAT_SCHEDULE = {
 AWX_INCONSISTENT_TASK_INTERVAL = 60 * 3
 
 AWX_CELERY_QUEUES_STATIC = [
-    six.text_type(CELERY_DEFAULT_QUEUE),
+    CELERY_DEFAULT_QUEUE,
 ]
 
 AWX_CELERY_BCAST_QUEUES_STATIC = [
-    six.text_type('tower_broadcast_all'),
+    'tower_broadcast_all',
 ]
 
 ASGI_AMQP = {