Symlinks in helm charts are not handled properly

[ejholmes]

Right now, the logic to generate a hash of a chart ignores any files that are symlinks

mani-diffy/pkg/helm/helm.go

Lines 317 to 328 in 3fdc849

	if !info.Mode().IsRegular() {
	resolvedInfo, err := resolvesTo(root)
	if err != nil {
	return err
	}
	if resolvedInfo.isDir {
	// TODO: figure out how to handle dirs and
	// symlinked dirs
	return nil
	}
	path = resolvedInfo.fileName
	}

If the chart includes any symlinks, changes to the files behind those symlinks won't cause the cache key to be busted, and won't trigger a re-render.

When hashing a chart, the hash should include all files under that directory, include the resolution of symlinks.