参考链接
https://codelabs.developers.google.com/codelabs/your-first-pwapp/#0
https://segmentfault.com/a/1190000008880637
https://zhuanlan.zhihu.com/p/25800461
https://developer.mozilla.org/zh-CN/Apps/Progressive
https://openweb.baidu.com/pwa-future/
https://lavas.baidu.com/doc
https://zhuanlan.zhihu.com/p/25524382
https://zhuanlan.zhihu.com/p/25524382
https://zhuanlan.zhihu.com/p/25459319
https://github.com/GoogleChrome/samples/blob/gh-pages/service-worker/basic/service-worker.js
https://developer.mozilla.org/zh-CN/docs/Web/Progressive_web_apps
http://web.jobbole.com/90314/
https://www.jianshu.com/p/7807cbd604de
