发送站内消息

        :param recipient_list: 收件人列表
        :param subject: 标题
        :param body: 内容（不能超过 1024 个字符）

def send_message(self, recipient_list, subject, body):
        """发送站内消息

        :param recipient_list: 收件人列表
        :param subject: 标题
        :param body: 内容（不能超过 1024 个字符）
        """
        url = 'http://www.shanbay.com/api/v1/message/'
        recipient = ','.join(recipient_list)
        data = {
            'recipient': recipient,
            'subject': subject,
            'body': body,
            'csrfmiddlewaretoken': self._request.cookies.get('csrftoken')
        }
        response = self.request(url, 'post', data=data)
        return response.ok