fix for playready in IE11

There are a variety of ways to prevent IE11 from rendering playready
video content. one of those ways is to layer the dropdown list over the
video tag. This moves the list of test content below the video element
and thus enables playready video to render.

I made this a pull request because I need some help with the test content list. I think it would work better if it was not a drop-down at all anymore. The hide/show toggle will control the list visibility instead. I would like to get rid of the drop-down but keep the styling. I think this would also mean that dropkick.js can be removed.

Feedback, objections and alternatives welcome.