Refactored OpenstackSwitching app

[DONE]
- Restructured to activate or deactivate switching and routing app separately
- Fixed to add or remove host when port is detected or vanished
- Use openstack node service to get integration bridges and data IP

[TODO]
- Remove use of OpenstackPortInfo
- Support installing flow rules for exising VMs
- Call security group update method when port update triggered from OpenStack

Change-Id: Ic0b2ac3f7ab07f0e20c97c6edfdd1928b9767baf
diff --git a/apps/openstacknode/BUCK b/apps/openstacknode/BUCK
index e614257..c9ad7ac 100644
--- a/apps/openstacknode/BUCK
+++ b/apps/openstacknode/BUCK
@@ -16,5 +16,5 @@
     category = 'Utility',
     url = 'http://onosproject.org',
     description = 'SONA Openstack Node Bootstrap Application.',
-    required_app = [ 'org.onosproject.ovsdb-base' ],
+    required_apps = [ 'org.onosproject.ovsdb-base', 'org.onosproject.drivers.ovsdb' ]
 )