Opening to other than localhost

I had an issue when using the default configuration threw a Docker Swarm.
I couldn't access the services becaus json-server was listening only to `localhost`.

Could you bring `-H 0.0.0.0` on the `run.sh` by default so others won't have the same problem ?

```sh
args="$@ -H 0.0.0.0 -p 80"
```