"kubebuilder update vendor" should update the Gopkg files as well

[perotinus]

Currently, kubebuilder update vendor only updates the vendor directory, not the Gopkg.lock and Gopkg.toml files. This leaves them out-of-sync, which is not ideal for understanding the versions of dependencies in the repo.

Alternatively, kubebuilder could not initialize a project with the Gopkg files, and leave that to the project's discretion.