title: Error while updating property 'X' in shadow node of type: RCTView
body: <p>I have a Item which receives a value from a props value.
  This value is not set correctly according to react-native error messaging.</p>
  
  <pre><code>export default class BarItem extends Component {
  
  constructor (props) {
      super(props);
  }
  
  propTypes : {
      color: PropTypes.string,
      barInterval: PropTypes.number,
  };
      const {color, barInterval} = this.props;
  
  render () {
      const baseStyle = {
          backgroundColor: color,
          marginRight: barInterval
      };
  
      return ( &lt;View style={Object.assign({}, baseStyle, {height: (empty * unitHeight)}) } /&gt; );
    }
  }
  </code></pre>
  
  <p>I am wondering why I can't update my value , and what a shadow node is, and how to prevent this in the future?</p>
  
  <p>EDIT: something to do with the value of 'barinterval' being a string but only accepting numbers. (wrong value given?)</p>