func (r *BoshRelease) readBoshRelease(rr io.Reader) error {
	w := pkg.NewTgzWalker(rr)
	w.OnMatch("release.MF", func(file pkg.FileEntry) error {
		return decodeYaml(file.Reader, &r.ReleaseManifest)
	})
	w.OnMatch("/jobs/", func(file pkg.FileEntry) error {
		job, jerr := r.readBoshJob(file.Reader)
		if jerr == nil {
			r.JobManifests[job.Name] = job
		}
		return jerr
	})
	err := w.Walk()
	return err
}
func (r *BoshRelease) readBoshRelease(rr io.Reader) error {
	w := pkg.NewTgzWalker(rr)
	w.OnMatch("release.MF", func(file pkg.FileEntry) error {
		return decodeYaml(file.Reader, &r.ReleaseManifest)
	})
	w.OnMatch("/jobs/", func(file pkg.FileEntry) error {
		job, jerr := r.readBoshJob(file.Reader)
		if jerr == nil {
			r.JobManifests[job.Name] = job
		}
		return jerr
	})
	err := w.Walk()
	return err
}
// readBoshRelease reads a bosh release out of the given reader into a new
// boshRelease struct