title: Aggregation not working with monger for mongodb version 3.6
body: <p>Mongo aggregation framework has some <a href="https://docs.mongodb.com/manual/reference/command/aggregate/" rel="nofollow noreferrer">changes in version 3.6</a>  Earlier aggregation queries with monger are not working even when we pass <em>:cursor {}</em> as an option. Is there any workaround or do we have to wait for the next monger release?. The error we get is specified below </p>
  
  <blockquote>
    <p>MongoCommandException Command failed with error 9: 'The 'cursor' option is required, except for aggregate with the explain argument' on server localhost:27017. The full response is { "ok" : 0.0, "errmsg" : "The 'cursor' option is required, except for aggregate with the explain argument", "code" : 9, "codeName" : "FailedToParse" }  com.mongodb.connection.ProtocolHelper.getCommandFailureException (ProtocolHelper.java:115)</p>
  </blockquote>