name exported in cluster nodes

[vsoch]

We currently have a "name" at the top, which largely gets parsed over if we just look at the graph attribute. E.g.,:

{
  "name": "cluster-red"
  "graph": {
    "directed": true,
    "nodes": {
      "0": {
        "label": "0",
        "metadata": {
...

I'm OK leaving it there for now - it shows up because the ClusterGraph Name is capitalized (and thus public). If we want it to be purely the graph we can remove it. I'm opening this issue as a future reminder to think about it, because it largely doesn't matter now.