Implement a debug command / commands

[izakp]

Currently hokusai [staging|production] run launches a new container, but implement a way to interact with a running container.

Kubectl provides the exec command to run a command or attach the current session to a running container and port-forward to attach a local port to a remote port

Proposal:

hokusai [staging|production] debug to call kubectl exec -t -i {pod} -- {command} and attach a session to the current shell for a given pod or select the first pod matching the application's selectors from all available running pods - accept an option to override the shell command, otherwise /bin/sh

hokusai [staging|production] attach to call kubectl port-forward {pod} {port}:{port} for a given pod or select the first pod matching the application's selectors from all available running pods - accept an option to specify the port to forward to/from localhost, otherwise 80