Resolve #92: Add default version install of docker, k8s, kata and kernel
Resolve #7: Ask user whether to uninstall existing docker of a different version before installing the specified(or default) version
Fix #13: Add sub-command ps to show running appv (untested, need to improve)
Resolve #92: Add default version install of docker, k8s, kata and kernel Resolve #7: Ask user whether to uninstall existing docker of a different version before installing the specified(or default) version Fix #13: Add sub-command ps to show running appv (untested, need to improve)