/logs/lively_events.log missing?

I had an error:
`Error: ENOENT, No such file or directory '/Users/gregor/couches/LivelyCouch/logs/lively_events.log'`
when running `node lively-events.js` manually. It worked after I created the `/logs/lively_events.log` manually.

Not sure if that's a bug or if I made something wrong?
