npm配置淘宝源

node-sass 安装失败，配置淘宝源

npm config set sass_binary_site=https://npm.taobao.org/mirrors/node-sass/      
npm config set phantomjs_cdnurl=https://npm.taobao.org/mirrors/phantomjs/       
npm config set electron_mirror=https://npm.taobao.org/mirrors/electron/       
npm config set registry=https://registry.npm.taobao.org