Update validate.sh to include Release-3 branch

scripts/validate.sh

@@ -23,7 +23,7 @@ mkdir -p /home/etsi/dev/build
 cd /home/etsi/dev/build
 rm -r -v *
 
-if [[ "$1" =~ .*-dev$ || "$1" =~ \d+(\.?\d)+ || "$1" == "master" ]]; then
+if [[ "$1" =~ .*-dev$ || "$1" =~ \d+(\.?\d)+ || "$1" == "master" || "$1" == "Release-3" ]]; then
 
 	cd /home/etsi/dev/robot2doc/robot2doc