Headless sim: has no walls

[Carter90]

There is no spawning of walls in run_headless_sim.sh currently.

Can be solved by something like this, I will make a pull for a refactor of the headless sim.

spawn="rosrun gazebo_ros spawn_model -sdf -file $dir/simulation/models/"
addWalls(){
	local roundType=$1 #defalt is final
	echo -e "$cyan Adding Wallz for $roundType round $reset"
	size=11.55 #final wall's distance from collection disk's cener
	[ $roundType ==  "prelim" ] && size=7.5 #if prelim round, final wall's distance from collection disk's cener
	$spawn\barrier_$roundType\_round/model.sdf -model "Barrier_North" -x $size -y 0 -z 0 -R 0 -P 0 -Y 0
	$spawn\barrier_$roundType\_round/model.sdf -model "Barrier_West" -x 0 -y $size -z 0 -R 0 -P 0 -Y 1.570796
	$spawn\barrier_$roundType\_round/model.sdf -model "Barrier_East" -x 0 -y -$size -z 0 -R 0 -P 0 -Y 1.570796
	$spawn\barrier_$roundType\_round/model.sdf -model "Barrier_South" -x -$size -y 0 -z 0 -R 0 -P 0 -Y 0
	echo -e "$green Done Adding Wallz for $roundType round $reset"
} #end addWalls```