Change the name of Component.render to Component.build in Effen

sky/examples/fn/widgets/drawerheader.dart

 part of widgets;
 
 class DrawerHeader extends Component {
 
   static Style _style = new Style('''
     display: flex;
     flex-direction: column;
     height: 140px;
     -webkit-user-select: none;
     background-color: ${BlueGrey[50]};
     border-bottom: 1px solid #D1D9E1;
     padding-bottom: 7px;
     margin-bottom: 8px;'''
   );
 
   static Style _spacerStyle = new Style('''
     flex: 1'''
   );
 
   static Style _labelStyle = new Style('''
     padding: 0 16px;
     font-family: 'Roboto Medium', 'Helvetica';
     color: #212121;'''
   );
 
   List<Node> children;
 
   DrawerHeader({ Object key, this.children }) : super(key: key);
 
-  Node render() {
+  Node build() {
     return new Container(
       style: _style,
       children: [
         new Container(
           key: 'Spacer',
           style: _spacerStyle
         ),
         new Container(
           key: 'Label',
           style: _labelStyle,
           children: children
         )
       ]
     );
   }
 }