Add license badge (#38)
Add license badge (#38)


cartographer-project/cartographer_turtlebot,damonkohler/cartographer_turtlebot,cartographer-project/cartographer_turtlebot,googlecartographer/cartographer_turtlebot,damonkohler/cartographer_turtlebot,wohe/cartographer_turtlebot,googlecartographer/cartographer_turtlebot,wohe/cartographer_turtlebot