Reduce the duplication of per-project specifics in the CircleCI config.
* Add docker repo variable, default to docker hub.
* Add make targets for docker push and tag latest.
Signed-off-by: Ben Kochie <superq@gmail.com>
This changes removes environment variables for jobs that don't need
them. It also removes one unnecessary test for the
docker_hub_release_tags job.
Signed-off-by: Simon Pasquier <spasquie@redhat.com>
