1.得到原本的镜像地址
npm get registry
> https://registry.npmjs.org/
设成淘宝的
npm config set registry http://registry.npm.taobao.org/
2.换成原来的
npm config set registry https://registry.npmjs.org/
3.mac 下的chromedriver老是下载不下来，解决办法
npm install chromedriver --chromedriver_cdnurl=http://cdn.npm.taobao.org/dist/chromedriver