Use []kubeadm.Arg instead of map[string]string when validating ExtraArgs in the API. Add new GetArgValue() and SetArgValue() utilities and tests in apis/kubeadm. Add new utils for constucting commands from and to a []kubeadm.Arg slice.
Signed-off-by: haoyun <yun.hao@daocloud.io>
Used T.Run API for kubeadm tests in app/util/