The best solution for me that I found is to use GitHub pages: https://pages.github.com/
The restriction is that you can use only one branch from the repo for keeping your scripts (namely: gh-pages branch)
sample usage
push test.js script to gh-pages branch of the REPO.
the script is out there at yourusername.github.io/REPO/test.js (it may take about 10 minutes to update)
Other solutions
http://rawgithub.com good for development as well as for production (with CDN) if you don't change your scripts (the CDN caches a particular url forever).
