pep8 and pylint fixes

edx_notifications/base_data.py

@@ -7,13 +7,8 @@
 import dateutil.parser
 import copy
 from datetime import datetime, timedelta
-
-import six
-from django.utils.functional import SimpleLazyObject, lazy
-from django.utils.translation import ugettext, ugettext_lazy
+from django.utils.translation import ugettext_lazy
 from freezegun.api import FakeDatetime
-from django.utils.functional import lazy
-from pytz.lazy import LazyDict
 
 
 class DateTimeWithDeltaCompare(datetime):

edx_notifications/const.py

@@ -161,4 +161,4 @@
     settings,
     "NOTIFICATION_ENFORCE_SINGLE_DIGEST_PREFERENCE",
     True
-)
+)

edx_notifications/stores/sql/models.py

@@ -440,4 +440,4 @@ def archive_deleted_user_notification(sender, instance, *args, **kwargs):  # pyl
     if const.NOTIFICATION_ARCHIVE_ENABLED:
         notification_archive_obj = SQLUserNotificationArchive()
         notification_archive_obj.__dict__.update(instance.__dict__)
-        notification_archive_obj.save()
+        notification_archive_obj.save()