title: elasticsearch search text return full array issue
body: <p>I am using <strong>mongoosastic</strong> for <strong>elasticsearch</strong>. and i done all setup and its working fine. but problem is result are not getting properly.</p>
  
  <p><strong>FILE:- mongoose and mongoosastic.</strong></p>
  
  <p><i></p>
  
  <pre><code>var mongoose = require('mongoose');
  var Schema = mongoose.Schema;
  var medicineSchema = require('./search')
  var mongoosastic = require("mongoosastic");
  
  var UserProfileSchema = new Schema({
      userId: String,
      username: String,
      address: String,
      number: Number,
      task: [{
          name: {
              type: String,
              es_boost: 2.0 // or es_indexed:true
          },
          taskCode: String,
      }]
  });
  UserProfileSchema.plugin(mongoosastic);
  UserProfileSchema.plugin(mongoosastic, {
      host: "localhost",
      port: 9200,
      //  ,curlDebug: true
  });
  UserProfile = module.exports = mongoose.model('UserProfile', UserProfileSchema);
  UserProfile.createMapping(function(err, mapping) {
      if (err) {
          console.log('error creating mapping (you can safely ignore this)');
          console.log(err);
      } else {
          console.log('mapping created!');
          console.log(mapping);
      }
  });
  </code></pre>
  
  <p></i></p>
  
  <p>And my search Query:</p>
  
  <p><i></p>
  
  <pre><code>var UserProfileSchema = require('../../app/models/user');
   UserProfileSchema.search({
          query_string: {
              query: name
          }
      }, function(err, result) {
          if (err) {
              callback({
                  RESULT_CODE: '-1',
                  MESSAGE: 'System error'
              });
          } else {
              callback({
                  RESULT_CODE: '1',
                  DATA: result
              });
          }
      });
  </code></pre>
  
  <p></i>
  Now my problem is if  <strong>task</strong> array has 3 object and when i search for task string i.e "abc" it will return full collection. with all task <strong>But i want only searched string object from  task array.</strong> i.e name :abc object</p>
  
  <p><i>
  ......</p>
  
  <pre><code>"task" [{
      name: 'abc',
      taskCode: 123
  },{
      name: 'xyz',
      taskCode: 123
  },{
      name: 'cdx',
      taskCode: 123
  }]
  </code></pre>
  
  <p></i></p>