This script is now responsible for making sure that the DefaultK8sVersion, NewestK8sVersion, and OldestK8sVersion supported by minikube have preloaded tarballs. It will be run on every PR as an automated release script for preloaded tarballs.
Include k8s binaries in preloaded tarball so that we can skip tranferring this over.
This increases the size of the tarball from around 430 MB to 500MB, but saves a couple seconds on start time.
Adds support for specifying kubernetes version and preloading docker
images into the kic base image.
Though this increases the kic base image by ~1.6G, it should improve
start latency in conjunction with removing 'kubeadm pull images' in
another PR.