Fix #4 infinite update trigger

Author: moshenskyD

src/components/growl/growl.vue

@@ -23,7 +23,7 @@
  name: 'vf-growl',
  data: function () {
  return {
- zIndex: 0,
+ zIndex: ++domHandler.zindex,
 
  container: null,
 
@@ -65,7 +65,6 @@
  return;
  }
 
- this.zIndex = ++domHandler.zindex;
  domHandler.fadeIn(this.container, 250);
 
  if (!this.sticky) {