Update validate-all.sh

# Copyright ETSI 2019

# See: https://forge.etsi.org/etsi-forge-copyright-statement.txt

echo "------ Switching to $1 folder --------"

cd $1

echo "------ Content of the folder ------"

ls

ls | grep yaml

echo "------ Validating all YAML files ------"

# If there are no YAML file, simply exit

if [ ! $(ls | grep yaml) ] ; then 

    echo "-- No YAML files."

fres=0

for i in ./*.yaml ;  do

    echo "-- Will validate: $i --"

    echo "----  Will validate: $i ----"

    swagger-cli validate "$i"

    res=$?

    fres=$(($fres||$res))