fix unit test and start Ryu from DCNetwork init

diff --git a/emuvim/example_topology.py b/emuvim/example_topology.py
index 5c459ce..eba751c 100755 (executable)
--- a/emuvim/example_topology.py
+++ b/emuvim/example_topology.py
@@ -109,8 +109,6 @@ def create_topology1():
     net.start()
     net.CLI()
     # when the user types exit in the CLI, we stop the emulator
-    # we need to explicitly stop the monitoring api, so the Ryu controller is also terminated
-    #mon_api.stop()
     net.stop()