Adding cassandra authentication whenever available
Adding cassandra authentication whenever available

Cassandra authentication can be enabled by specifying username and password in
testbed.py. All the services accessing cassandra should use those credentials
Partial-Bug: 1551969

Change-Id: Id40120b467d37bd83e8f2c1339ced44085f0947e

tcpcloud/contrail-controller,tcpcloud/contrail-controller,tcpcloud/contrail-controller,tcpcloud/contrail-controller,tcpcloud/contrail-controller,tcpcloud/contrail-controller