Remove unused imports.

tests/test_middleware.py

@@ -6,10 +6,8 @@
 
 """
 
-from django.conf import settings
 from django.contrib.auth import get_user_model
 from django.contrib.auth.models import AnonymousUser
-from django.core.exceptions import ImproperlyConfigured
 from django.test import TestCase
 from django.test.client import RequestFactory
 from django.test.utils import override_settings, modify_settings