updated docs.

We are using k8s pkg/version in minikube cmd to print out the
default version.  This was falling back to the defaults in pkg/version/base.go which were an ugly format string.  This wasn't actually being passed into cluster.go because we didn't pass the string in if was a default version.

Fixed .deb file make target, there was an issue in that git does not track empty directories which the template dir had and the build relied on.  Dir creation is now done in Makefile

Also add notes to the RELEASING.md doc, and a make target to test the release.

files.  Updated to reflect talk regarding creating .deb for kubectl.
Added make deb in Makefile.

url) and to copy files from host to the vm instead of curl within vm.
Also made it so that sshutil.Transfer is done via a Reader.

This broke during the last Makefile cleanup, we were ln'ing the same path to itself.

Cutting v0.6.0 release.  Bumped version in Makefile and releases.json.  Added v0.6.0 to CHANGELOG.md