Fix syslog output levels

This should be working now for syslog under both ruby 1.9 & 2.0.

In order to see all syslog messages on Mac OS X, I had to put this near the top of my ```/etc/asl.conf``` file, and get syslogd to reload it (```sudo killall -HUP syslogd```).

```
# Flapjack messages saved to flapjack.log
? [= Sender flapjack] file /var/log/flapjack.log
? [= Sender flapjack] ignore
```

The default system.log file seemed to only log messages at WARN and above.