Find alternative to duplicating config variables for replication factors

[OneCricketeer]

In #3 , I copied out some config variables and referenced them in the same file.

Ideally, Ansible/Vagrant should be able to just let me set the variables like

kafka:
  broker:
    config:
      offsets.topic.replication.factor: 1

However, this appears to overwrite the entire kafka.broker subtree, and not only kafka.broker.config, so the playbook fails trying to first find kafka.broker.group (and other sub-nodes)