Fixing flake8 errors

graphene/contrib/django/__init__.py

@@ -9,4 +9,4 @@ from graphene.contrib.django.fields import (
 )
 
 __all__ = ['DjangoObjectType', 'DjangoNode', 'DjangoConnection',
-           'DjangoModelField']
+           'DjangoModelField', 'DjangoConnectionField']

graphene/contrib/django/fields.py

@@ -58,5 +58,3 @@ class DjangoModelField(FieldType):
 
     def get_object_type(self, schema):
         return get_type_for_model(schema, self.model)
-
-

graphene/contrib/django/filter/__init__.py

@@ -1,3 +1,6 @@
 from .fields import DjangoFilterConnectionField
 from .filterset import GrapheneFilterSet, GlobalIDFilter
 from .resolvers import FilterConnectionResolver
+
+__all__ = ['DjangoFilterConnectionField', 'GrapheneFilterSet',
+           'GlobalIDFilter', 'FilterConnectionResolver']

graphene/contrib/django/resolvers.py

@@ -41,5 +41,3 @@ class SimpleQuerySetConnectionResolver(BaseQuerySetConnectionResolver):
 
     def get_order(self):
         return self.args.get('order', None)
-
-

graphene/contrib/django/tests/filter/test_resolvers.py

@@ -2,7 +2,7 @@ import pytest
 from django.core.exceptions import ImproperlyConfigured
 
 try:
-    import django_filters
+    import django_filters  # noqa
 except ImportError:
     pytestmark = pytest.mark.skipif(True, reason='django_filters not installed')
 else: