promoter: assure we log container-push
promoter: assure we log container-push

* get reusable container-push command in logs (copy/paste ready)
* assure each container-push ansible execution is logged in individual
  file.

Change-Id: Ie60d891d5b687fb10214f62f234211a0ff4630b5

redhat-openstack/rdo-infra,rdo-infra/ci-config,rdo-infra/ci-config,rdo-infra/ci-config,redhat-openstack/rdo-infra,redhat-openstack/rdo-infra,redhat-openstack/rdo-infra,rdo-infra/ci-config