Fixed some flake8 errors.

Originally I added migrations to flake8 exclude because of long lines
in migration files, but there are other directories named migrations we
do want to check. We are not warning on line lengths yet anyway.

setup.cfg

@@ -3,7 +3,7 @@ doc_files = docs extras AUTHORS INSTALL LICENSE README.rst
 install-script = scripts/rpm-install.sh
 
 [flake8]
-exclude=build,.git,./django/utils/dictconfig.py,./django/utils/unittest.py,./django/utils/lru_cache.py,./django/utils/six.py,./django/conf/app_template/*,./django/dispatch/weakref_backports.py,*/migrations/*
+exclude=build,.git,./django/utils/dictconfig.py,./django/utils/unittest.py,./django/utils/lru_cache.py,./django/utils/six.py,./django/conf/app_template/*,./django/dispatch/weakref_backports.py
 ignore=E123,E128,E265,E501,W601
 max-line-length = 119
 

tests/migrations/test_migrations_backwards_deps_1/0001_initial.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
 
-from django.db import migrations, models
+from django.db import migrations
 
 
 class Migration(migrations.Migration):

tests/migrations/test_migrations_backwards_deps_1/0002_second.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
 
-from django.db import migrations, models
+from django.db import migrations
 
 
 class Migration(migrations.Migration):