Going through this guide: http://blog.pact.io/2018/07/16/publishing-pact-verification-statuses-to-github/ and according to the webhook docs: https://docs.pact.io/pact_broker/advanced_topics/api_docs/webhooks, I found that Dynamic Variable substitution for ${pactbroker.githubVerificationStatus} can have either of these 3 values: failure, pending, success. For ${pactbroker.bitbucketVerificationStatus} the values can be: INPROGRESS, SUCCESSFUL, FAILED.
But for Gitlab, the CI we are using, commit statuses are pending, running, success, failed, canceled.