add unit test case for pkg/k8sversion/version_test.go
add unit test case for pkg/k8sversion/version_test.go

Signed-off-by: ZouYu <fe87c7a761ef1939f89153b2599d7d74395f947c@cn.fujitsu.com>

kubernetes/kops,justinsb/kops,justinsb/kops,justinsb/kops,kubernetes/kops,kubernetes/kops