Add missing args.py used by draft-3 tests.

Author: Peter Amstutz

draft-3/draft-3/args.py

@@ -0,0 +1,7 @@
+#!/usr/bin/env python
+import sys
+import json
+import os
+args = [os.path.basename(a) for a in sys.argv[1:]]
+with open("cwl.output.json", "w") as f:
+    json.dump({"args": args}, f)