Creates an role

{
  "data": {
    "attributes": {
      "name": "Custom role",
      "reference": "ANY-EXTERNAL-REFEFERNCE",
      "reference_origin": "ANY-EXTERNAL-REFEFERNCE-ORIGIN",
      "metadata": {
        "foo": "bar"
      }
    },
    "relationships": {
      "organization": {
        "data": {
          "id": "XGZwpOSrWL"
        }
      }
    }
  }
}