mark IOPub channel tests

IPython/zmq/tests/test_message_spec.py

@@ -399,6 +399,9 b' def test_complete():'
         yield nt.assert_true(name in matches, "Missing match: %r" % name)
 
 
+# IOPub channel
+
+
 @dec.parametric
 def test_stream():
     flush_channels()