Replace the irker detector

[ezio-melotti]

The irker detector has been used to post updates to the #python-dev-notifs IRC channel (see the bugs.sls file).

• Find a replacement
• Set up the replacement
• Remove irker. python/psf-salt#232

[ammaraskar]

This one is handled by https://github.com/TkTech/notifico out of the box which we are already using for Github push notifications on IRC.

[ezio-melotti]

It seems that this is already configured to notify about issues and issue comments, so there shouldn't be anything else to do.

[ezio-melotti]

I confirm that it works: