Update the _build_network_info_model method

DHC-1474

The parent method changed in the havana cycle so lets copy
it and cherry pick the few changes we added

Change-Id: I56495a0bb08b357e5fff92c24a2bb25d496cb5b4
Signed-off-by: Rosario Di Somma <rosario.disomma@dreamhost.com>
Remove unused import

Change-Id: I685665a3390a99aef484920e8253b3cde206d70f
Signed-off-by: Rosario Di Somma <rosario.disomma@dreamhost.com>
Merge pull request #14 from rodis/feature/update-to-havana

Update the _build_network_info_model method