Push connectors images to artifactory registry

The current connectors release images are only pushed to the old Docker registry (datapwn).

This makes it difficult to use these images on the K8s dev cluster as we only have access to the artifactory registry (artifactory.datapwn.com/tlnd-docker-dev/talend/) so it would be nice to add this push as part of the release process so as to avoid doing it manually by different developers.