Try workaround for video rendering error:

"NoMethodError at /refinery/videos/10 undefined method `url' for nil:NilClass"
Try upgrading from Video.js 4.3 to 4.6.
Try to use our own version of Video.js.
Revert last change, trying to serve own Video.js; didn't work well.
Try to disable cache.
Try adding dep on youtube.js.
Try to add youtube support.