Adding blank line between comment tag and package name in doc.go. So
that the comment tags such as '+k8s:deepcopy-gen=package' do not show up
in GoDoc.
Introduce the v1alpha1 version to the Kubernetes storage API. And add a
new VolumeAttachment object to that version. This object will initially
be used only by the new CSI Volume Plugin. Eventually existing volume
plugins can be refactored to use it too.
