Add the basic mininet integration lab box

The 'mininet' system that is used by the integration lab is a system
that combines mininet, netopeer / NETCONF and has PostgreSQL 9.3
installed to support a VTN coordinator also be brought up.

Change-Id: I95f7c38419985f6f0a6bb258a4173feaa8bfd42b
Signed-off-by: Andrew Grimberg <agrimberg@linuxfoundation.org>