Allow SleekTest to wait longer when checking for sent stanzas.

Now timeouts at 0.5sec instead of 0.1sec, which should prevent test
failures from stanzas being delayed longer than usual.

sleekxmpp/test/sleektest.py

@@ -578,7 +578,7 @@ class SleekTest(unittest.TestCase):
             raise ValueError("Uknown matching method: %s" % method)
 
     def send(self, data, defaults=None, use_values=True,
-             timeout=.1, method='exact'):
+             timeout=.5, method='exact'):
         """
         Check that the XMPP client sent the given stanza XML.