By reverting django.core.signing to Django 1.11.8 version Django-Q works
This is not designed as a 'good' solution just to show where I think the
problem is.
In Django 1.10 MIDDLEWARE_CLASSES is set to deprecated and is removed in Django 2.0.
The SessionAuthenticationMiddleware is also removed from Django 2.0 and was already
unconditionally enabled in Django 1.10.