[FEATURE] Make `exo logs` print the exit code if the process is stopped

[ryfow]

Is your feature request related to a problem? Please describe.

Sometimes when I exo logs <service-name>, the process is stopped but it just seems like it isn't logging at the moment.

Describe the solution you'd like

I think printing <process name> exited with status 1 or something similar would help.

Describe alternatives you've considered

Having exo logs exit if no processes are are still running is also a possibility.

[brandonbloom]

Great suggestion. Thanks.