title: Parsing iterative json objects using retrofit/gson
body: <p>I'm being sent something like the following from a server I'm required to connect to:</p>
  
  <pre><code>{
    "properties": {
      "prop1": {
        "type": "string",
        "title": "string"
      },
      "prop2": {
        "type": "string",
        "title": "string"
      },
      "prop3": {
        "type": "string",
        "title": "string"
      },
      "prop4": {
        "type": "string",
        "title": "string"
      }
    }
  }
  </code></pre>
  
  <p>Obviously it would be more ideal for the server to send an array of objects with an id field, but I can't change it unfortunately. The numbers after "prop" can go up ad infinitum (though realistically won't go above 50 or so), is there a graceful way to handle this in Retrofit 2/GSON? or do I need to intercept this call and do it manually each time?</p>
  
  <p>In a perfect world I'd like to end up with an array of "Prop" pojos that have an id field (1, 2, 3, etc), or even with "prop1", "prop2" etc in a field in each object.</p>