Run on Carina

[smashwilson]

As an intermediate state before we take on #139, it might be neat to get Deconst running on Swarm. I bet we could simplify deconst/deploy a ton. Some thoughts about this:

• The Carina interlock container might be useful. Can it terminate TLS for us?
• I'd rather not point DNS directly at a Carina endpoint. Instead, let's keep our Cloud Load Balancer, but add a single node that points to the Carina-hosted load balancer container. That will let us upgrade to new Carina environments, more recent Docker and Swarm releases, and so on without incurring downtime.
• Within the deploy repo, I'd prefer to maintain the following properties for script/deploy, whatever it's backed by:
  • It should be able to go the whole way from an account with nothing on it to a fully-running system. (Meaning, I prefer to avoid any manual steps; this keeps it handy as a panic switch.)
  • It should support multiple "instances" on the same account. (I often spin up a personal instance on the same Rackspace account that I use to host the deconst docs.)
  • It should be generic enough to be reused for many deconst instances.

/cc @everett-toews