Merge branch 'feature-agreement_notify' into 'master' 新增微信预扣费通知支持 See merge request api-team/pingpp-nodejs!15
fix coupon_template; new Buffer() -> Buffer.from()
不指定 ssl_version
update changelog
update docs/agreement.md
合并账户系统接口
version 2.0.13
2.0.11, examples updated
更新签名生成机制。格式化 example 代码