beta - IRC notifications for the QA team

This is to add an IRC bot (icinga-wm) into #wikimedia-qa
which will output only the services for which
betalabs is a contact.

- add special contact to contactgroup betalabs
- add custom notification commands to write to separate log
- configure echoirc to join channel and read from that log

like we recently also did for Wikidata

requires a contact to be added in private repo

Change-Id: Ie946b8b9ed67034752d7d8a6fcacb742e04247f3
Merge "beta - IRC notifications for the QA team" into production