title: jenkins build job on PR accepted
body: <p>I want to trigger a Jenkins build job on a particular action i.e. PR accepted. I tried using Jenkins Poll SCM without giving any schedule, but that gets trigger on when the PR is raised.</p>
  
  <p>How can I make sure that the build is only triggered when PR is merged/accepted.</p>
  
  <p>Also I am using github.</p>