Added scope separator to Spotify provider
Removed refresh token and constructor parameters for API
Added getAlbum method
Added getAlbums method
Added getAlbumTracks method
Added getArtist method
Added getArtists method
Added getArtistAlbums method
Added PHPDoc blocks and Pagination entities
Added getArtistTopTracks method
Added getArtistRelatedArtists method
Added getTrack method
Added getTracks method
Added AccessTokenExpiredException
Added getUserProfile method
Added getCurrentUser method
Added getPlaylist and getUserPlaylists methods