title: Start multiple Animated.timing at once with React Native
body: <p>I'm trying to start multiple React Native animations at once, with one callback for all animations. The example works fine, but I don't like the fact, that I have to start one after the other and having only one animation with a callback. Is there a more elegant way?</p>
  
  <pre class="lang-js prettyprint-override"><code>Animated.timing(this.state.opacity, {
      toValue: 0,
      duration: 300
  }).start();
  
  Animated.timing(this.state.height, {
      toValue: 0,
      duration: 300
  }).start(() =&gt; {
      // callback
  });
  </code></pre>