http://es6.ruanyifeng.com/#docs/async
https://www.cnblogs.com/gaoshang212/p/5639773.html
https://segmentfault.com/q/1010000008290224
Browserify
https://github.com/browserify/browserify#usage
https://github.com/babel/babelify
http://lisperator.net/uglifyjs/
https://github.com/browserify/watchify
原文：https://www.cnblogs.com/javalzy/p/11670804.html