Scm Activity add-on now supports and provides web-hook REST end-point for GitHub.
Available from add-on version 2.0.2
STEP-1
On GitHub org, go to repository settings > Webhooks > Click Add Webhook
Define Payload URL e.g. http://JIRASERVER/rest/scmactivity/1.0/changeset/github/push
Content Type: application/json
Choose Just the push event
Check Active checkbox
Click Update/Add webhook.
STEP-2
Verify payload delivery.
