Can't watch your demo

[bachue]

When I try to open http://www.joepettersson.com/demo/jquery-github-widget/ to watch your demo, I got this error:

Uncaught ReferenceError: j is not defined jquery.github.min.js:17
Uncaught TypeError: Cannot call method 'toLowerCase' of undefined jquery.github.min.js:17

So I'm afraid I can't see your work. My browser is the latest Chrome, can you help to fix it? Thanks!