use working material bootstrap package

use working material bootstrap package
Based on the docs for `slide` (http://api.jqueryui.com/slider/#event-slide), you should use `ui.value`, not `$(...).slider('value')`. The latter represents the current volume, the former represents the new volume that is about to be set when the current `slide` event finishes. You can see the difference by `console.log`ing both.