TV auth keys get reset after container is recreated
I have found that the default locations, `~/.homebridge/.webosTv/keyFile_xxx` for the key file and `~/.homebridge/.webosTv` do not persist when the Docker container is recreated.

All TVs have to be authorized again.

I have manually specified the locations, this persists and there's no need to reauthorize.

```json
"keyFile": "/homebridge/webos/<TV_NAME>/keyfile",
"prefsDir": "/homebridge/webos/<TV_NAME>"
```

The `oznu/homebridge` uses `/homebridge` as the `WORKDIR`. So `~/` corresponds to `/root`, which does not persist.

```sh
agneev@always-on ~> docker exec -it homebridge sh
/homebridge # cd ~/
~ # echo $PWD
/root
```