Update print statements to print function calls

To make the code more Python 3 compatible.

Author: tjelvar-olsson

cwltool/main.py

@@ -470,7 +470,7 @@ def load_job_order(args, t, stdin, print_input_deps=False, relative_deps=False,
 
     if not job_order_object and len(t.tool["inputs"]) > 0:
         if toolparser:
-            print(u"\nOptions for %s " % args.workflow)
+            print(u"\nOptions for {} ".format(args.workflow))
             toolparser.print_help()
         _logger.error("")
         _logger.error("Input object required, use --help for details")