Merge changes from topic "OOM-1816"

* changes:
  Molecule test for infrastructure playbook.
  Add the prepare-package-repository role
  Add prepare-nexus role
  Add prepare-nginx role
  Add the prepare-dns role
  Add prepare-vncserver role
  Allow unsafe writes when modifying resolv.conf
  Add nexus_come_up_wait_retries variable to nexus role
  Remove docker restart condition from docker role