* Update go-containerregistry
Update go-containerregistry since it can now handle image names of the
format repo:tag@digest.
Should fix#535.
Thanks @ViceIce for the fix!
* update go-containerregistry again
* dep ensure and use k8schain
* checkpoint
* fix vendoring, stuff builds
* Use k8schain for pushes too
* Use NewNoClient
* update ggcr dep
* Move k8schain usage to image_util.go
* Vendor changes for go-containerregistry switch.
* Manual changes for go-containerregistry switch.
The biggest change is refactoring the tarball unpacking.
* Pull more of container-diff out.
* More vendor removals.
* More unit tests.