'Verify HTTP 400 is returned for requests with an invalid timestamp.'

@ddt.data(to_timestamp((datetime.datetime.now(pytz.UTC) - datetime.timedelta(0, ((60 * 15) + 1)))), u'invalid')
def test_post_with_invalid_timestamp(self, timestamp):

    request_uuid = self._create_credit_request_and_get_uuid()
    response = self._credit_provider_callback(request_uuid, u'approved', timestamp=timestamp)
    self.assertEqual(response.status_code, 400)
