Log Message:
audio/spotify-player: update to 0.4.0

Brief description of major changes
-Implement ShowActionsOnSelectedItem (#13) and ShowActionOnCurrentTrack (#18)
 commands which list available actions (BrowseArtist, SaveToLibrary,
 BrowseRecommendations, etc) on a Spotify item (track, album, artist, playlist).
-Upgrade majority of dependencies (#14) which includes a big rspotify v0.11.0
 migration.
-Integrate Spotify recommendation API (#17).
-And many other code refactors and improvements.