'Allows editing the users while skipping the username check, so we can have Unicode username with no problems.
The username is marked read-only regardless of `ENABLE_UNICODE_USERNAME`, to simplify the bokchoy tests.'

def get_readonly_fields(self, *args, **kwargs):

    django_readonly = super(UserAdmin, self).get_readonly_fields(*args, **kwargs)
    return (django_readonly + ('username',))
