Fix for player not rendering on computed videoId
Fix for player not rendering on computed videoId

When I have the videoId as a computed value, your watcher tries update the player. But I think the player is not ready yet because it throuws an JS error:
[Vue warn]: Error in watcher "videoId"
TypeError: this.player[name] is not a function

This small fix 'listens' for the property to exist on the player and then runs it
kaorun343/vue-youtube-embed,kaorun343/vue-youtube-embed