Rework slam streamer for easier testing

tracking/devices/factory.py

@@ -0,0 +1,10 @@
+from tracking.devices.mock_lidar import MockLidar
+from rplidar import RPLidar
+import tracking.lidar_loader as loader
+
+
+def get_lidar(connection: str):
+    if connection == 'TEST':
+        return MockLidar(loader.load_scans_bytes_file("tracking/out.pickle"))
+    else:
+        return RPLidar(connection)