cyclades: Add shared field in the API for networks

Add a "shared" field in the API reply of networks to be compatible with
Neutron API. This field has the same value as the "public" field.

snf-cyclades-app/synnefo/api/networks.py

@@ -187,6 +187,7 @@ def network_to_dict(network, detail=True):
         d['created'] = api.utils.isoformat(network.created)
         d['status'] = state
         d['public'] = network.public
+        d['shared'] = network.public
         d['router:external'] = network.external_router
         d['admin_state_up'] = True
         d['subnets'] = subnet_ids