kubernetes: create Service Environment Variables

[bradrydzewski]

Kubernetes creates environment variables for each linked service:

FOO_SERVICE_HOST=<the host the service is running on>
FOO_SERVICE_PORT=<the port the service is running on>

We should automatically create these environment variables for services in the compiler. They would be ignored by the Kubernetes runtime, but included in the Docker runtime. The goal would be to encourage use of environment variables instead of hostnames, for portability between engines.