remove duplicate functions

addressed #9 (closed)

Headers/Public/VLCMLAlbum.h

@@ -43,12 +43,7 @@ typedef NS_ENUM(NSUInteger, VLCMLSortingCriteria);
 - (instancetype)init NS_UNAVAILABLE;
 
 - (VLCMLIdentifier)identifier;
-- (NSString *)title;
 - (uint)releaseYear;
-- (NSString *)shortSummary;
-- (NSURL *)artworkMrl;
-
-- (VLCMLArtist *)albumArtist;
 
 - (NSArray<VLCMLMedia *> *)tracksWithSortingCriteria:(VLCMLSortingCriteria)criteria desc:(BOOL)desc;
 - (NSArray<VLCMLMedia *> *)tracksByGenre:(VLCMLGenre *)genre sortingCriteria:(VLCMLSortingCriteria)criteria desc:(BOOL)desc;