A simple suboptimal dns server which forward requests to multiple servers according to domains.

Invocation:
    > dispatching-dns <config.yaml>

Sample Configuration:
    address: 192.168.1.1
    user: nobody
    group: nogroup
    resolver:
      !dispatch
        rules:
          - ['google.com', 1]
        targets:
          - !proxy
            cache_size: 5000
            upstreams:
              - !service
                address: 192.168.0.1
          - !record
            resolver:
              !proxy
                cache_size: 500
                upstreams:
                  - !service
                    address: 8.8.8.8
                  - !service
                    address: 8.8.4.4
            log: addresses.log
