Ignore .elasticbeanstalk/
Add npm start script.
WIP: Attempt at an Elastic Beanstalk config.
added X-Content-Type-Options as reason why browsers don't execute some JS

`<script src="https://raw.github.com/user/repo/master/filename.js">` would load if GitHub didn't send out X-Content-Type-Options on the `raw.github.com` domain.
(ref: https://code.google.com/p/chromium/issues/detail?id=180007)
Relay If-Modified-Since. Don't relay Cache-Control and Pragma.
Merge branch 'patch-1' of git://github.com/tomvangoethem/rawgithub
Tweak wording.