youtube-api package update

Updated the youtube-api npm package to the latest version.

`youtube-api@v0.2.0` has a new feature: key authentication (see the [changelog](https://github.com/IonicaBizau/youtube-api#v020) for more information)

This will not break any functionality from `v0.1.1`. Anyway, if you find bugs, report them. :smile: 

You did a great job with mediacenterjs!