Scrollspy Doesn't Support Chinese ID Targets

Created by: wzpan

Hello, I found Scrollspy doesn't support Chinese ID Targets.

In order to reproduce the bug, I post a gist. It looks almost the same to the example from official Doc. A slight difference is that I modify one element's id("mdo") into a Chinese ID ("艾姆滴欧").

When you view the html file in your browser, you can see that it can spy all the target elements except that element with Chinese ID.