Imports of openapi-gen command

PathSynopsis
github.com/golang/glogPackage glog implements logging analogous to the Google-internal C++ INFO/ERROR/V setup.
k8s.io/gengo/argsPackage args has common command-line flags for generation programs.
k8s.io/kubernetes/cmd/libs/go2idl/openapi-gen/generators
path/filepathPackage filepath implements utility routines for manipulating filename paths in a way compatible with the target operating system-defined file paths.