Make docstring for networking service consistent with other services

cloudbridge/cloud/interfaces/provider.py

@@ -146,8 +146,8 @@ class CloudProvider(object):
         .. code-block:: python
 
             networks = provider.networking.networks.list()
-            network = provider.networking.networks.create(
-                           label="DevNet", cidr_block='10.0.0.0/16')
+            subnets = provider.networking.subnets.list()
+            routers = provider.networking.routers.list()
 
         :rtype: :class:`.NetworkingService`
         :return:  a NetworkingService object