Fixed a couple flake8 warnings.

tests/apps/apps.py

@@ -23,5 +23,3 @@ class NotAConfig(object):
 
 class NoSuchApp(AppConfig):
     name = 'there is no such app'
-
-

tests/apps/tests.py

@@ -2,7 +2,6 @@ from __future__ import absolute_import, unicode_literals
 
 from django.apps import apps
 from django.apps.registry import Apps
-from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 from django.db import models
 from django.test import TestCase, override_settings