Code review comment for lp:~townsend/libertine/smoke-test-workaround

Ah - I found that it's all based out of the lp:libertine-testing branch. Not sure how it's all getting installed on slave-0 and running, though.

I also think my previous comment is actually only a config option for LXD. Another option might be the MIRROR env variable, which I think we might be able to set globally before the smoke test run based on this link: https://dev.launchpad.net/Running/LXC.