yarn修改为淘宝源

和npm修改淘宝源的的步骤差不多

1. 查看当前源

   yarn config get registry

2. 临时修yran源
   yarn save package_name --registry https://registry.npm.taobao.org/

3. 修改yarn源为taobao源
   yarn config set registry https://registry.npm.taobao.org/

4. 修改yarn源为官方源
   yarn config set registry https://registry.yarnpkg.com