Testing the `loki` sink

Run Loki in docker:

docker run -d --name=loki -p 3100:3100 grafana/loki

Configure the loki sink:

sinks:
  out:
    type: loki
    inputs:
      - source0
    endpoint: http://localhost:3100
    encoding:
      codec: json
    out_of_order_action: accept
    labels:
      host: hostname