bug: when version is not there, it should prompt error immediately

as it support kubeflow with version v1.6, the following commmand should prompt error
`
./multikf.linux add nodegpu --export_ports 80:80,443:443 --use_gpus=1 --with_kubeflow=true --kubeflow_version=v1.6 --with_password=12341234
`

as kubeflow_version should be `v1.6.0` not `v1.6`.
the current behavior is just ignoring it.