Add a submit field to tests.util.NullAuthForm
Add a submit field to tests.util.NullAuthForm

The ‘submit’ field used to be inherited from AuthForm, but since that was removed in 0b1ac12c35512783c8f03aa3c0b9e2f428d2d9bf it had to be defined in NullAuthForm.
paxswill/evesrp,eskwire/evesrp,eskwire/evesrp,eskwire/evesrp,paxswill/evesrp,paxswill/evesrp,eskwire/evesrp