By using netlify functions and github API, this webapp notifies GitHub for the netlify deploy status of your site.

1. Deploy this repo as a new netlify site, say https://<NAME>.netlify.app
2. In the deploy settings of the new site, create an environment variable JWS_SECRET and put
   some random text in it. It is a custom secret used to verify the identity of the triggerer.
3. Go to GitHub to generate a personal access token. Check out scope repo:status.
4. Then go to the deploy notifiction settings of the your own site, add outgoing webhooks for "Deploy started", "Deploy succeeded" and "Deploy failed" by putting https://<NAME>.netlify.app/.netlify/functions/notify?token=<TOKEN> in "URL to notify" and the value of JWS_SECRET in "JWS secret token". <TOKEN> should be replaced by the token that you generated from GitHub earlier.