allow the app and ec2-user's to do 'supervisorctl (status|restart|...)'

After seeing this for the 4th time, it got pretty annoying:

```
app@host $ supervisorctl status
error: <class 'socket.error'>, [Errno 13] Permission denied: file: <string> line: 1
```

So, now app and ec2-user are allowed to get status and manage processes with having to change user.