Ability to work with a video element as well

# tl;dr

You also want to inspect the audio shape of a video element.

# Example

```js
var video = peaks.init({
  mediaElement: document.querySelector('video')
});

var audioPeaks = peaks.init({
  mediaElement: document.querySelector('audio')
});
```

![screen shot 2014-03-11 at 17 03 39](https://f.cloud.github.com/assets/138627/2388458/d36921ae-a941-11e3-84f6-7101754254fb.png)