Fix script

bin/ensure-up-to-date

@@ -2,7 +2,7 @@
 # this bash script run the scripts for the 'mature' generators
 # it ensures that all changes are commited into the 'samples/' folder
 
-echo "# START SCRIPT: $SCRIPT"
+echo "# START SCRIPT: $0"
 
 echo "IMPORTANT: this script should be run by the CI (e.g. Shippable) to ensure that the 'samples/' folder is up to date."
 echo "Please press CTRL+C to stop or the script will continue in 5 seconds."
@@ -13,7 +13,7 @@ sleep 5
 ./bin/ruby-petstore.sh
 
 # Check:
-if ! `git diff-index --quiet HEAD -- `; then
+if [ -n "$(git status --porcelain)" ]; then
     echo "UNCOMMITTED CHANGES ERROR"
     echo "There are uncommitted changes in working tree after execution of 'bin/ensure-up-to-date'"
     git status