Dump basic network info  in the test_network_basic_ops

Add minimal debug debug capability for basic network informations,
These information, especially the nat rules in the router namespaces
 usually very helpful.

Change-Id: I8840cb5e388fc8b674b66f8de4e25754ccbe0863
Add update-volume test

* change method _volume_create_get_delete for VolumesGetTest
* add method update_volume for VolumesClientJSON & VolumesClientXML

Change-Id: I71c2a0e1979767ffe453baf7e3b86e378725906c
Merge "Dump basic network info  in the test_network_basic_ops"
Merge "Add update-volume test"