[deps] Fix so it works with older mopidy

tests/test_frontend.py

@@ -1,5 +1,7 @@
 from unittest import mock
 
+from mopidy.models import Playlist
+
 from mopidy_smartplaylists.frontend import SmartPlaylistsFrontend
 
 
@@ -14,11 +16,16 @@ class TestSmartPlaylistsFrontend:
             "refresh_interval": "0",
         }
         core = mock.Mock()
+        core.library.search.return_value.get.return_value = []
+        core.playlists.lookup.return_value.get.return_value = None
+        core.playlists.save.return_value.get.return_value = Playlist(
+            name="test", uri="dummy:pl", tracks=[]
+        )
 
         frontend = SmartPlaylistsFrontend(config, core)
         frontend.on_start()
 
-        core.library.search.assert_called()
+        assert core.library.search.call_count == 2
 
     def test_on_start_without_recipes(self):
         config = mock.Mock()
@@ -39,10 +46,16 @@ class TestSmartPlaylistsFrontend:
     def test_playlists_loaded_with_interval(self):
         config = mock.Mock()
         config.get.return_value = {
+            "decades": "1980",
             "playlist_prefix": "[Smart]",
             "refresh_interval": "24",
         }
         core = mock.Mock()
+        core.library.search.return_value.get.return_value = []
+        core.playlists.lookup.return_value.get.return_value = None
+        core.playlists.save.return_value.get.return_value = Playlist(
+            name="test", uri="dummy:pl", tracks=[]
+        )
 
         frontend = SmartPlaylistsFrontend(config, core)
         frontend.playlists_loaded()