Improved tests

dav_registration/tests/test_apps.py

@@ -1,6 +1,5 @@
 from django.apps import apps
 from django.core.exceptions import ImproperlyConfigured
-from six import string_types
 
 from dav_base.tests.generic import AppSetting, AppsTestCase
 
@@ -9,5 +8,5 @@ class TestCase(AppsTestCase):
     app_config = apps.get_app_config('dav_registration')
 
     settings = (
-        AppSetting('privacy_policy', ImproperlyConfigured, string_types),
+        AppSetting('privacy_policy', ImproperlyConfigured, str),
     )