title: React Native transforms with pivot point
body: <p>I want to rotate a <code>Text</code> component with an angle of <code>-90deg</code>. The component should be rotated from the left corner instead of middle. I am using below codes:</p>
  
  <pre><code>render() {
       return (
              &lt;View style = {{flex : 1}}&gt;
                  &lt;View style={styles.sidebar}&gt;
                      &lt;Text style={styles.lblSideBar} numberOfLines = {1} &gt;DUMMY TEXT&lt;/Text&gt;
                  &lt;/View&gt;
              &lt;/View&gt;);
  }
  
  const styles = StyleSheet.create({
    sidebar : {
      flex : 1,
      flexDirection : 'row',
      alignItems : 'flex-end',
      justifyContent : 'center',
      width : 30,
    },
    lblSideBar : {
        bottom : 20,
        transform : [{rotate : '-90deg'}],
    }
  });
  </code></pre>
  
  <p>I want the bottom space of 20px, but as rotation is happening from center(by default) the text is covering the bottom area after rotation. Please suggest how to achieve that?
  Also <code>react-native</code> needs the support of <strong><code>pivotPoint</code></strong> or <strong><code>anchorPoint</code></strong> or <strong><code>transformOrigin</code></strong> so that this property can be achieved easily.</p>