Feature request: server-oriented setup command

[tlhunter]

I'd like to see the ability to run a setup command that doesn't need to exit before the benchmarks run. Maybe like a setup_watch or server option in the JSON configuration. Then, once the tests complete, the long running setup child is killed.

This would be useful for running servers where the server doesn't need to daemonize. I find handing these daemonized processes gets tricky. One could track pids and have a teardown command kill the pid but I bet it's a common enough use case that it's worth supporting in sirun.

If one were to benchmark redis-server then a long running server option would make for a clean interface.

Also, I'm not sure if there's a better name for all of this. An attached vs detached child?

[bengl]

I think this may be the same as #45?

[tlhunter]

It is!