rocker: add tests

rocker: add tests

Add some basic test for rocker to test L2/L3/L4 functionality.  Requires an
external test environment, simp, located here:

https://github.com/scottfeldman/simp

To run tests, simp environment must be installed and a suitable VM image built
and installed with a Linux 3.18 (or greater) kernel with rocker driver support
enabled.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Message-id: 1426306173-24884-8-git-send-email-sfeldma@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>