Suppress command line help for --disable-validate to discourage people

from using it.

Author: Peter Amstutz

cwltool/argparser.py

@@ -215,7 +215,8 @@ def arg_parser():  # type: () -> argparse.ArgumentParser
                         help="Will be passed to `docker run` as the '--net' "
                              "parameter. Implies '--enable-net'.")
     parser.add_argument("--disable-validate", dest="do_validate",
-                        action="store_false", default=True, help="Skip CWL document validation.")
+                        action="store_false", default=True,
+                        help=argparse.SUPPRESS)
 
     exgroup = parser.add_mutually_exclusive_group()
     exgroup.add_argument("--enable-ga4gh-tool-registry", action="store_true", help="Enable resolution using GA4GH tool registry API",