title: Is there a GitHub issue webhook?
body: <p>So I am unclear on GH docs as to whether their webhook supports issue notification. It sounds like it support webhooks. However when I set up test endpoints nothing comes, even when I test payload.</p>
  
  <p>I am using ultrahook.com as well as requestb.in to catch requests but nothing comes. </p>
  
  <p>Are github webhooks even working? Has anyone got it to work?</p>