youtube_player_iframe v3.0.3

• Fixed issues related to Fullscreen.
• Added onInit & onFullscreenChange callbacks to YoutubePlayerController.
• Added Migrating to v3 section in the docs.
• Listed Swipe up/down to enter/exit fullscreen mode as a feature in the docs.
• Deprecated autoPlay param in YoutubePlayerParams, as it's no longer used.
• Removed hasPlayed, position & buffered from YoutubePlayerValue, as these values can be accessed through YoutubePlayerController.