Adding (-x | --stop) option back to runner.py

fixes bug 931608

Change-Id: I355a3bba38367c820a0eddc006ef480e5134b317

nova/testing/runner.py

@@ -344,6 +344,7 @@ class NovaTestRunner(core.TextTestRunner):
 
 def run():
     flags.FLAGS.register_cli_opt(cfg.BoolOpt('hide-elapsed', default=False))
+    flags.FLAGS.register_cli_opt(cfg.BoolOpt("stop", short='x', default=False))
     argv = flags.FLAGS(sys.argv)
     logging.setup()