npm安装超时，使用淘宝镜像
1.切换淘宝镜像：
npm config set registry https://registry.npm.taobao.org
2.切换其他：
npm ---- https://registry.npmjs.org/
cnpm --- http://r.cnpmjs.org/
taobao - http://registry.npm.taobao.org/
eu ----- http://registry.npmjs.eu/
au ----- http://registry.npmjs.org.au/
sl ----- http://npm.strongloop.com/
nj ----- https://registry.nodejitsu.com/