SMTP notifier 1.19.0

What's Changed

• Updating the /go/cloudbuild version to include new enum types by @gaPanza in #183
• Support secrets in HTTP URLs by @ekupershlak in #184
• Monthly update for November 23 by @fayfaychan in #185

New Contributors

• @gaPanza made their first contribution in #183
• @ekupershlak made their first contribution in #184
• @fayfaychan made their first contribution in #185

Full Changelog: bigquery-1.17.0...smtp-1.19.0