Send a request to cancel an order, return the response.

        Arguments:
        order_id - the order id to cancel

def cancel_order(self, order_id):
        """
        Send a request to cancel an order, return the response.

        Arguments:
        order_id - the order id to cancel
        """
        request = '/v1/order/cancel'
        url = self.base_url + request
        params = {
            'request': request,
            'nonce': self.get_nonce(),
            'order_id': order_id
        }

        return requests.post(url, headers=self.prepare(params))