only supervise web, worker, urgentworker and clock proctypes

I'll throw this one out there. Let me know what you think.

I have another plugin (https://github.com/michaelshobbs/dokku-app-predeploy-tasks) that runs some things prior to deploy in the container that doesn't need supervisor to keep running. This PR filters on only the standard "daemon" proctypes. 

Also removes the need for a newline at the end of the Procfile