'Try removing requirement status with a invalid user_id'

def test_invalid_user(self):

    set_credit_requirements(self.course.id, [{'namespace': 'grade', 'name': 'grade', 'display_name': 'Grade', 'criteria': {'min_grade': 0.8}}])
    retval = self.service.set_credit_requirement_status(self.user.id, self.course.id, 'grade', 'grade')
    self.assertIsNone(retval)
    retval = self.service.remove_credit_requirement_status(0, self.course.id, 'grade', 'grade')
    self.assertIsNone(retval)
