Fix AVS response to sync [issue #44]

alexa_client/alexa_client/connection.py

@@ -73,7 +73,7 @@ def synchronise_device_state(self, device_state, authentication_headers):
             headers=headers,
         )
         response = self.connection.get_response(stream_id)
-        assert response.status == http.client.NO_CONTENT
+        assert response.status in ( http.client.NO_CONTENT, http.client.OK )
 
     def send_audio_file(
         self, audio_file, device_state, authentication_headers,