Running in containers causes problems due to stdout conflicts

Hi there,

I'm running this KCL in a Docker container, however due to the fact that my code writes log entries (to stdout to make docker log aggregation easier) it conflicts with KCL entries and displays unnecessary errors and in some cases causes the KCL to crash.

I'll get output like this coming through:

```bash
SEVERE: Received error line from subprocess [[2017-09-13 02:16:10.104][scheduler][INFO]: Deduplicated stream items - original length: 1, filtered length: 1] for shard shardId-000000000000
```

Is there any way to get around this other than resorting to logging to separate files? Ideally it would be great if I could configure it to use a custom unix socket (similar to how say php-fpm or nginx-uwsgi work) so that it doesn't conflict with services logging to stdout / stderr