Fix kernel.inprocess tests

IPython/kernel/inprocess/socket.py

@@ -58,7 +58,7 b' class DummySocket(HasTraits):'
         return self.queue.get_nowait()
 
     def send_multipart(self, msg_parts, flags=0, copy=True, track=False):
-        msg_parts = map(zmq.Message, msg_parts)
+        msg_parts = list(map(zmq.Message, msg_parts))
         self.queue.put_nowait(msg_parts)
         self.message_sent += 1