Duplicated album detection improved

not case sensitive.

examples/artist_discography.py

@@ -34,7 +34,7 @@ def show_artist_albums(id):
     print('Total albums:', len(albums))
     unique = set()  # skip duplicate albums
     for album in albums:
-        name = album['name']
+        name = album['name'].lower()
         if not name in unique:  
             print(name)
             unique.add(name)