'Verify the endpoint returns HTTP 400 if the course is not a valid course key.'

def test_post_invalid_course_key(self):

    course_key = u'not-a-course-id'
    response = self.post_credit_request(self.user.username, course_key)
    self.assert_error_response(response, u'[{}]    is    not    a    valid    course    key.'.format(course_key))
