WHT-31 

Pull request for review from @elmariofredo 
this should be targeting frontline node first create in pillar.examle key app.domain, set it to `example.com` then put here `DNODE_HOST:  {{ salt['grains.get']('circle') }}.{{ pillar['app']['domain'] }}` this way we don't have to setup domain directly in config.

https://github.com/trexglobal/Sfym-infrastructure/blob/master/salt/sfym/files/app/config/application.yml#L27