A state container that bundles postgres along with a shared volume. This allows
all stellar-core state to reside on a single container such that the main
stellar-core container can be swapped out without a full state reload.
Typically you'll want to run this container with the same env file as the stellar-core container so the command will look something like this:
$ docker run --name scc-node1-state \ -p 5541:5432 \ --env-file single.env \ -d stellar/stellar-core-state