Add IRCbot plugin support

This publisher enables Jenkins to send build notífications via IRC and lets you
interact with Jenkins via an IRC bot.

Change-Id: I9e676f7c54033327409c10b998e2a5218147ce9a
Implements: blueprint jenkins-job-builder-irc
Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>
Merge "Add IRCbot plugin support"