Enhance IPv6 scenario - dual network testing

Dual Network is where instead of 2 subnets with different IP versions on the
same network, we use 2 neutron-networks, each with its own subnet.
That way, instead of each server having a single vNIC with 2 IP addresses,
each server has 2 vNICs.

This patch adds tests with dual network for the test_network_v6 scenarios.

In Cirros (and other guest images) only the 1st vNIC is set UP on boot by
default. This patch solved the problem by turning the 2nd vNIC on.

Also, a minor fix to remote_client that strips ":" from the output of
get_nic_name.

Change-Id: I237310e9a8f75551069ffe49b3280c0ab2183664
3 files changed