hack/versions: extract most from vendor.conf

This sets `$what_VERSION` and `$what_REPO` for runc, cni, containerd and
kubernetes based on vendor.conf, removing the need to duplicate things in
hack/versions.

With this `update_hack_versions` becomes redundant so remove it and both calls.

Since CONTAINERD_REPO is now unconditionally set we can also simplify the
fetching of vendor.conf in update-vendor.sh a bit, so do so. Further since
`*_REPO` are now unconditionally set we can support alternative clone paths for
all of these repos by adjusting checkout_repo to make the 3rd argument
non-optional and always passing it. Since `CRITOOL_VERSION` is not coming from
`vendor.conf` (since it is not used from Go code) we manually set
`CRITOOL_REPO` for consistency.

The final wrinkle is that `k8s.io/kubernetes` is has a Go specific redirect in
the form of HTML meta headers returned from https://k8s.io/kubernetes/?go-get=1
which point to the real repo to clone. Parsing that in shell is tricky so just
hardcode that.

Fixes #540.

Signed-off-by: Ian Campbell <ijc@docker.com>

hack/test-e2e-node.sh

@@ -59,12 +59,11 @@ fi
 GOPATH=${GOPATH%%:*}
 
 # Get kubernetes
-KUBERNETES_REPO="https://github.com/kubernetes/kubernetes"
 KUBERNETES_PATH="${GOPATH}/src/k8s.io/kubernetes"
 if [ ! -d "${KUBERNETES_PATH}" ]; then
   mkdir -p ${KUBERNETES_PATH}
   cd ${KUBERNETES_PATH}
-  git clone ${KUBERNETES_REPO} .
+  git clone https://${KUBERNETES_REPO} .
 fi
 cd ${KUBERNETES_PATH}
 git fetch --all