Change to ArgumentDefaultsHelpFormatter.

Changed from this:
formatter_class=argparse.RawTextHelpFormatter

To this:
formatter_class=argparse.ArgumentDefaultsHelpFormatter

This greatly improves the formatting of the help text.

Change-Id: Ie3ad6afe0b3cda50e1b032c37a20ff22733de9bd
Signed-off-by: Michael Walsh <micwalsh@us.ibm.com>
diff --git a/bin/validate_plug_ins.py b/bin/validate_plug_ins.py
index 15d02a1..33ace31 100755
--- a/bin/validate_plug_ins.py
+++ b/bin/validate_plug_ins.py
@@ -30,7 +30,7 @@
     description="%(prog)s will validate the plug-in packages passed to it." +
                 "  It will also print a list of the absolute plug-in" +
                 " directory paths for use by the calling program.",
-    formatter_class=argparse.RawTextHelpFormatter,
+    formatter_class=argparse.ArgumentDefaultsHelpFormatter,
     prefix_chars='-+')
 
 # Create arguments.