Long running docker processes per handler

[softprops]

Each request invokes a fresh container. Let's see if there isn't a way to manage longer lived containers for faster response times

[softprops]

I think this should be possible with a change to the way logs are fetched https://docs.docker.com/engine/reference/commandline/logs/

Atm we ask for all logs for a container. We could instead get just the logs since the time of a given request