Rewrite unit test to make it working on all versions of django

Author: dotsbb

graphene_django/tests/test_views.py

@@ -457,14 +457,18 @@ def test_handles_invalid_json_bodies(client):
     }
 
 
-def test_handles_django_request_error(client, settings):
-    settings.DATA_UPLOAD_MAX_MEMORY_SIZE = 1000
-    valid_json = json.dumps(dict(test='x' * 1000))
+def test_handles_django_request_error(client, monkeypatch):
+    def mocked_read(*args):
+        raise IOError("foo-bar")
+
+    monkeypatch.setattr("django.http.request.HttpRequest.read", mocked_read)
+
+    valid_json = json.dumps(dict(foo='bar'))
     response = client.post(url_string(), valid_json, 'application/json')
 
     assert response.status_code == 400
     assert response_json(response) == {
-        'errors': [{'message': 'Request body exceeded settings.DATA_UPLOAD_MAX_MEMORY_SIZE.'}]
+        'errors': [{'message': 'foo-bar'}]
     }