Configure gerritbot for IRC notification

To start the service:

• Add the gerritbot role to desired host in the inventory: /etc/software-factory/arch.yaml:

inventory:
  - hostname: managesf.sftests.com
    roles:
      - gerritbot

• Set the gerritbot configuration in /etc/software-factory/sfconfig.yaml:

gerritbot:
  botname: sfbot
  disabled: false

• Re-apply: sfconfig

Then finish the configuration with the user configuration