Bug 1254 - Increase UT coverage

Signed-off-by: Martin Bobak <mbobak@cisco.com>
Removed implementation of RPC get-node-ip-address

implementation of RPC get-node-ip-address from flow-node-inventory is removed.
This RPC is not needed anymore. IP address is stored in datastore.

Signed-off-by: Martin Sunal <msunal@cisco.com>