Support for Multiple Sinks

[eytan-avisror]

Readme mentions one of the goals of this project is Support for multiple sinks should be configurable, but looking at the code I don't see that it currently supports using multiple sinks.
It would be good to support this, for example stdout + s3sink.

the configuration json object should parse a list instead of a string and have the config under some object, for example:

apiVersion: v1
kind: ConfigMap
metadata:
  name: eventrouter
  namespace: eventrouter
data:
  config.json: |-
    {
      "sink": ["stdout", "s3sink"],
      "stdout": {},
      "s3sink": {}
    }

Am I missing something? is this currently somehow possible?