anchor.diff:  ----
   log:
     level: warn
  -  appenderDef:
  -  - test
  +  appenderRefs:
  +    - test
     loggers:
       com.foo:
         level: debug
  -      appenderDef:
  -      - test
  +      appenderRefs:
  +        - test
       com.example:
         level: debug
     appenders:
  
positive.code: |console appender
  |A list of appenders to output logs to. See below.
  
  |`appenderDef`
  |none
  |A list of references to appenders. If it's added to child logger only, then the
                           child logger will write logs with this named appender. If the appender added
  
negative.code: 
  |`useLogbackConfig`
  |`false`
  |If true, all other logback settings are ignored and the user is expected to provide its own config file per http://logback.qos.ch/manual/configuration.html[Logback documentation]. This is only needed for a few advanced options not directly available via Bootique config.
  |===
  
  === log.appenders
  