Install crane
This MR adds the 'crane' utility to the alpine image. This is an alternative to Red Hat's 'skopeo' utility with similar functionality. Skopeo has proven to have issues with the OKD registries, and it would be desirable to find an alternative.
See the docs:
https://github.com/google/go-containerregistry/blob/master/cmd/crane/doc/crane.md
Example usage with gitlab CI:
https://github.com/google/go-containerregistry/blob/master/cmd/crane/README.md#using-with-gitlab
This results in an additional static binary of size 8.8MB added to the image.