Configure zuul to trigger jobs on special comments
Configure zuul to trigger jobs on special comments

Configure zuul to retrigger check jobs when a comment with just
'recheck' in the comment text is left on a change. Retrigger approval
jobs when a comment with just 'reverify' in the comment text is left
on a change.

Change-Id: If3d21b31f19fc84211703b8cad05654e3da16c48

open-switch/infra_puppet-jenkins,open-switch/infra_puppet-jenkins