Fixed minor bug when editing sdn-controller. Modified test_RO.py according to...

Fixed minor bug when editing sdn-controller. Modified test_RO.py according to openmano behaviour. Added additional tests for SDN

Change-Id: Iacb895c0f95e24e0e1b1c1b33a8072f8edd40534
Signed-off-by: Pablo Montes Moreno <pablo.montesmoreno@telefonica.com>