I did some investigation, here are my findings:

 + Django's TestCase creates `client` in `_pre_setup` (https://github.com/django/django/blob/master/django/test/testcases.py#L199)

 + test_utils' TestCase overloads `_pre_setup` and while it copies some of the code there, doesn't copy the client creation line. (https://github.com/jbalogh/test-utils/blob/master/test_utils/__init__.py#L219)

We can either pull request against test_utils and fix that there or use what we have in this pull request. Thoughts?