Merge branch '6-safe-default-for-is_valid' into 'master'

Resolve "safe default for is_valid"

Closes #6

See merge request !3

validate_workflow.sh

@@ -425,7 +425,7 @@ scan_file() {
     trap "" SIGINT
     debug "scan_file, === entering protected area ==="
     if [ "$STAGE" = "any" ]; then
-        is_valid=0
+        is_valid=1
         for stage in upcoming current; do
             cmd=$(prepare_cmd "$MODE" "$ftype" "$stage" | sed -e "s#FILE#$filename#")
             is_valid=$(exec_cmd "$cmd" "$ftype" "$MODE" "$stage" "$logname")