Adds support for multiple network interfaces

Previously, containers could only have a single network interface.
This patch allows the kube infra to support multiple interfaces
on containers. docker-spotter runs on minions and connects to the
docker daemon, receives events and executes commands on the CLI.

Connection pattern:
container_eth1<>kbr1<>kube_eth1<>neutron_net
Merge pull request #8 from danehans/multi_int

Adds support for multiple network interfaces