Permission issues
Hello,

I'm attempting to run this image with user namespaces enabled in the docker daemon, but am getting errors when running oznu/homebridge. I have the following set when I launch the container:

```sh
--userns=host --privileged --net=host
```

I've also tried setting `-e PUID=0 -e PGID=0`. I've also tried setting these to the user and group that docker normally remaps.

Unfortunately, every combination I try it seems the start up script doesn't have permission to execute commands like chmod/chown or even npm install. Basically every command throws "Operation not permitted".

Obviously I know this isn't ideal and is sort of weird when using namespaces, but right now I'm just trying to see if I can get it running. :)

Thoughts?