'Test that the response from get_sale_records is in json format.'

def test_get_sale_records_features_json(self):

    for i in range(5):
        course_registration_code = CourseRegistrationCode(code='sale_invoice{}'.format(i), course_id=self.course.id.to_deprecated_string(), created_by=self.instructor, invoice=self.sale_invoice_1, invoice_item=self.invoice_item, mode_slug='honor')
        course_registration_code.save()
    url = reverse('get_sale_records', kwargs={'course_id': self.course.id.to_deprecated_string()})
    response = self.client.post(url, {})
    res_json = json.loads(response.content)
    self.assertIn('sale', res_json)
    for res in res_json['sale']:
        self.validate_sale_records_response(res, course_registration_code, self.sale_invoice_1, 0, invoice_item=self.invoice_item)
