[Improvement] Support Vue.use to register a component (#401)

packages/checkbox/index.vue

@@ -21,16 +21,12 @@
 </template>
 
 <script>
-import Icon from '../icon';
+import { create } from '../utils';
 import findParent from '../mixins/find-parent';
 
-export default {
+export default create({
   name: 'van-checkbox',
 
-  components: {
-    Icon
-  },
-
   mixins: [findParent],
 
   props: {
@@ -106,5 +102,5 @@ export default {
       }
     }
   }
-};
+});
 </script>