Goal: 

• In the join workflow, we have Pendo feature tracking of the User's journey through the registration wizard UI.  But we are missing one thing - we do not emit an event when the user completes the CLI-based registration.  We can do this server-side upon the POST /domains/<domain-id> request.
• As a result, we will be able to see whether users complete the ipa-hcc-server registratation, but fail to return to the web UI to complete the wizard.  It may give hints that the UI/UX should be tweaked to promote customer success.

Acceptance Criteria:

• Emit pendo tracking event upon successful execution of the POST /domain/<id> resource.