Fixed several flake8 errors, including one where a test wouldn't be run

tests/invalid_models_tests/test_ordinary_fields.py

@@ -6,7 +6,7 @@ import unittest
 from django.core.checks import Error, Warning as DjangoWarning
 from django.db import connection, models
 from django.test.utils import override_settings
-from django.utils.timezone import make_aware, now
+from django.utils.timezone import now
 
 from .base import IsolatedModelsTestCase
 

tests/utils_tests/test_timezone.py

@@ -109,7 +109,7 @@ class TimezoneTests(unittest.TestCase):
             timezone.make_naive(datetime.datetime(2011, 9, 1, 13, 20, 30), EAT)
 
     @unittest.skipIf(pytz is None, "this test requires pytz")
-    def test_make_aware(self):
+    def test_make_aware2(self):
         self.assertEqual(
             timezone.make_aware(datetime.datetime(2011, 9, 1, 12, 20, 30), CET),
             CET.localize(datetime.datetime(2011, 9, 1, 12, 20, 30)))