Local CDN response resource without cache header

[lawrenceching]

Hi, dev of local-cdn,

I noticed that local-cdn return resource very simply without any cache policy header.
It leads to browser request data every time.

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Test Case:
Use chrome to visit getbootstrap.org, measures how much time chrome spend to load jquery.min.js

First time: 498ms
Second time with local-cdn disabled: 78ms (from disk cache)
Second time with local-cdn enabled: 254ms

[james-fray]

I am not sure if setting cache is possible when you are redirecting to a local resource.

On the test page getting each resource takes like 20ms
See, https://cdn.rawgit.com/james-fray/local-cdn/master/test/text.html

[james-fray]