Implement a simple docker-capable orchestrator service

[rtyler]

The orchestrator service should really only be driven by the event bus, and be responsible for spinning up agents in whatever environment they should be spun up in.

I'm thinking right now that what would be the simplest for me to run would be something that interacts with Azure Container Instances, but I imagine I'll need numerous orchestrators which can provision different shapes of runtimes.

Just docker alone should be good enough for now.