populate floorplan name to msg

Non-critical change. This helps in debugging in here: osrf/rmf_schedule_visualizer#78

building_map_tools/building_map_server/building_map_server.py

@@ -80,6 +80,7 @@ def level_msg(self, level):
         if level.drawing_name:
             image = AffineImage()
             image_filename = level.drawing_name
+            image.name = image_filename.split('.')[0]
             image.encoding = image_filename.split('.')[-1]
             image.scale = level.transform.scale
             image.x_offset = level.transform.translation[0]