Fixed double dashes in default minion swarm names

tests/minionswarm.py

@@ -39,7 +39,7 @@ def parse():
     parser.add_option('--name',
             '-n',
             dest='name',
-            default='ms-',
+            default='ms',
             help=('Give the minions an alternative id prefix, this is used '
                   'when minons from many systems are being aggregated onto '
                   'a single master'))