relocate homebridge.log to /homebridge/logs
On an RPI system where we want to reduce IO writes, we want to use a `tmpfs` mounting for logs.

In [45-user-data](https://github.com/oznu/docker-homebridge/blob/master/root/etc/cont-init.d/45-user-data) the directory `/homebridge/logs` is created. Yet, the actual logs produced by the system dump logs to `/homebridge/homebridge.log` . Using a file under `/homebridge` makes the use of `tmpfs` impossible since it requires a directory mapping.

Solution: relocate `/homebridge/homebridge.log` to `/homebridge/logs`

