yarn 下包的时候提示错误：There appears to be trouble with your network connection. Retrying
原因： yarn超时，终端多次提示There appears to be trouble with your network connection. Retrying
解决如下：
//查看代理
git config list
//删除代理
git config delete registry
//或者删除代理
git config delete proxy
//更换淘宝镜像
yarn config set registry https://registry.npm.taobao.org
