another spelling correction
another spelling correction

changed invisibly to invisible
BCLab-UNM/SwarmBaseCode-ROS,BCLab-UNM/SwarmBaseCode-ROS,BCLab-UNM/SwarmBaseCode-ROS,BCLab-UNM/SwarmBaseCode-ROS,BCLab-UNM/SwarmBaseCode-ROS,BCLab-UNM/SwarmBaseCode-ROS