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

        Arguments:
        amount -- quoted decimal amount of BTC to purchase
        price -- quoted decimal amount of USD to spend per BTC
        side -- 'buy' or 'sell'
        client_order_id -- an optional client-specified order id (default None)
        symbol -- currency symbol (default 'btcusd')
        type -- the order type (default 'exchange limit')

def new_order(self, amount, price, side, client_order_id=None,
                  symbol='btcusd', type='exchange limit', options=None):
        """
        Send a request to place an order, return the response.

        Arguments:
        amount -- quoted decimal amount of BTC to purchase
        price -- quoted decimal amount of USD to spend per BTC
        side -- 'buy' or 'sell'
        client_order_id -- an optional client-specified order id (default None)
        symbol -- currency symbol (default 'btcusd')
        type -- the order type (default 'exchange limit')
        """
        request = '/v1/order/new'
        url = self.base_url + request
        params = {
            'request': request,
            'nonce': self.get_nonce(),
            'symbol': symbol,
            'amount': amount,
            'price': price,
            'side': side,
            'type': type
        }

        if client_order_id is not None:
            params['client_order_id'] = client_order_id

        if options is not None:
            params['options'] = options

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