Allow scaling process up/down in an existing overmind session

[adibsaad]

So if I had a Procfile with web and worker, and I started a new session with only web e.g. overmind start -l web, I'm not able to start a worker process unless I kill the session and restart it with -l web,worker.

I would expect the scaling option, -m to be able to do that e.g. overmind s -m worker=1, but it complains that an overmind session is already running.

system | Listening at ./.overmind.sock
overmind: it looks like Overmind is already running. If it's not, remove ./.overmind.sock and try again

[DarthSim]

Hey Adib!

Well, this would require a lot of changes as Overmind initially wasn't meant for dynamically scaling the processes. However, it's not impossible, so I'll keep it here. I'd not expect this feature in the nearest feature though.