Add spotify queue

tests/test_spotify.py

@@ -64,6 +64,10 @@ class SpotifyTest(unittest.TestCase):
         self.client.seek(90000)
         self.assertEqual(self.fake.seeks, [90000])
 
+    def test_queue_lists_what_comes_next_in_order(self):
+        self.fake.queue = [{"name": "Old King"}, {"name": "Natural Beauty"}]
+        self.assertEqual([i["name"] for i in self.client.queue()], ["Old King", "Natural Beauty"])
+
     def test_playback_reports_the_device_and_whether_it_plays(self):
         self.fake.player = {"device": {"id": "dev-1", "name": "Lego Room"}, "is_playing": True}
         player = self.client.playback()