title: Merge two objects with ES6
body: <p>I'm sure this question has been asked before but I can't quite find the answer I'm looking for, so here goes:</p>
  
  <p>I have two objects, as follows:</p>
  
  <pre><code>const response = {
    lat: -51.3303,
    lng: 0.39440
  }
  
  let item = {
    id: 'qwenhee-9763ae-lenfya',
    address: '14-22 Elder St, London, E1 6BT, UK'
  }
  </code></pre>
  
  <p>I need to merge these together to form this:</p>
  
  <pre><code>item = {
    id: 'qwenhee-9763ae-lenfya',
    address: '14-22 Elder St, London, E1 6BT, UK',
    location: {
      lat: -51.3303,
      lng: 0.39440
    }
  }
  </code></pre>
  
  <p>I know I could do it like this:</p>
  
  <pre><code>item.location = {}
  item.location.lat = response.lat
  item.location.lng = response.lng
  </code></pre>
  
  <p>However, I feel that this is not the best way to do it anymore, because ES6 introduced the cool destructuring/assignment stuff; I tried deep object merging but it's unfortunately not supported :( I also looked through some ramda functions but couldn't see anything that was applicable.</p>
  
  <p>So what is the best way to merge these two objects using ES6? </p>