使用https模块爬https协议的图片，不能够直接在浏览器中成功展示图片,why?
var fs = require('fs');
var https = require('https');
var request = require('request');
https.createServer(function(req,res){
request('https://www.imooc.com/static/img/index/logo_new.png')
.pipe(res)
})
.listen(8090)
