title: How to autogenerate id if there is no id in document with elasticjs v5.0
body: <p>I am trying to add documents, according to elastic search documents, we can add document, even if we dont provide id... <a href="https://www.elastic.co/guide/en/elasticsearch/guide/current/index-doc.html" rel="nofollow noreferrer">See Here</a></p>
  
  <p>I am trying to add a document even if it doesnt have any ID. in elastic search, how can i do that?
  My current code looks like this</p>
  
  <pre><code>var params = _.defaults({}, {
      index: index,
      type: type, //'customer'
      id: data.id || null,
      body: data
  })
  debug(params)
  return this.client.create(params);
  </code></pre>
  
  <p>The above code gives this error</p>
  
  <blockquote>
    <p>{
      "error": "Unable to build a path with those params. Supply at least index, type, id"
    }</p>
  </blockquote>
  
  <p>Any hint would help, thanks </p>