今天安装tyarn时，报错如下：

request to https://registry.npm.taobao.org/tyarn failed, reason: certificate has expired

原来淘宝镜像过期了，需要重新搞一下

记录一下解决过程：

1.查看当前npm配置

npm config list

2.清空缓存

npm cache clean --force

3.修改淘宝镜像

npm config set registry https://registry.npmmirror.com

4.查看 registry是否更改成功

npm config list

5.ok啦