Add fnichol to CODEOWNERS for butterfly component.
.buildkite @christophermaier @fnichol @scotthain
components/backline @fnichol @baumanj
components/builder* @chefsalim @raskchanky
-components/butterfly* @christophermaier @reset @baumanj
+components/butterfly* @christophermaier @reset @baumanj @fnichol
components/common @fnichol @baumanj @raskchanky
components/eventsrv* @reset @raskchanky
components/hab* @reset @fnichol @christophermaier @chefsalim @baumanj @elliott-davis @raskchanky @eeyun
