Moved playlist tests in a dedicated directory

api/tests/playlists/test_models.py

@@ -0,0 +1,20 @@
+
+
+def test_can_create_playlist(factories):
+    tracks = factories['music.Track'].create_batch(5)
+    playlist = factories['playlists.Playlist']()
+
+    previous = None
+    for track in tracks:
+        previous = playlist.add_track(track, previous=previous)
+
+    playlist_tracks = list(playlist.playlist_tracks.all())
+
+    previous = None
+    for idx, track in enumerate(tracks):
+        plt = playlist_tracks[idx]
+        assert plt.position == idx
+        assert plt.track == track
+        if previous:
+            assert playlist_tracks[idx + 1] == previous
+        assert plt.playlist == playlist