send switch state to change event vuematerial#503 (vuematerial#504)

Author: mathieucivel

src/components/mdSwitch/mdSwitch.vue

@@ -67,7 +67,7 @@
       },
       changeState(checked, $event) {
         if (typeof $event !== 'undefined') {
-          this.$emit('change', $event);
+          this.$emit('change', checked, $event);
 
           if (!$event.defaultPrevented) {
             this.checked = checked;