Finalized creation of the TRI Carla Challenge 4 scenario. At this point, we should be able to create a specialized scenario for the 4th event. The scenario will be able to do the following.

1. Use the Town03 map provided by Carla.
2. Spawn actors around the traffic circle up to the maximum allowed.
3. Remove actors when they are far enough away from the traffic circle and spawn new ones in their place.
4. Randomize the scenario based on a seed value, including, when actors spawn and the type of actor