'Create a new order.
Arguments:
contribution (int): The contribution amount.
course_id (CourseKey): The course to purchase.
Keyword Arguments:
expect_success (bool): If True, verify that the response was successful.
expect_status_code (int): The expected HTTP status code
Returns:
HttpResponse'

def _create_order(self, contribution, course_id, expect_success=True, expect_status_code=200):

    url = reverse('verify_student_create_order')
    data = {'contribution': contribution, 'course_id': course_id, 'processor': None}
    response = self.client.post(url, data)
    self.assertEqual(response.status_code, expect_status_code)
    if (expect_status_code == 200):
        json_response = json.loads(response.content)
        if expect_success:
            self.assertEqual(set(json_response.keys()), PAYMENT_DATA_KEYS)
        else:
            self.assertFalse(json_response['success'])
    return response
