[RFR]Added function list_image_openshift (#106)
[RFR]Added function list_image_openshift (#106)

* Added function list_image_openshift
* Update openshift.py
* Changed the function name to list_docker_registry as to avoid confusion with the other function in Kubernetes class that returns the list of registries
RedHatQE/mgmtsystem,mfalesni/mgmtsystem