add VHD images w/ k8s 1.11.4 and k8s 1.12.2 (#4146)
add VHD images w/ k8s 1.11.4 and k8s 1.12.2 (#4146)


Azure/acs-engine,Azure/acs-engine,Azure/acs-engine,jackfrancis/acs-engine,jackfrancis/acs-engine,jackfrancis/acs-engine,Azure/acs-engine,jackfrancis/acs-engine,Azure/acs-engine,jackfrancis/acs-engine