fix for issue 14

Author: Shaegi

src/components/presets/BulletList.vue

@@ -1,6 +1,6 @@
 <template>
   <vue-content-loading v-bind="$attrs" :width="230" :height="height">
-    <template v-for="i in rows">
+    <template v-for="i in rows" :key="i">
       <circle :key="i" cx="8" :cy="getYPos(i, 8)" r="8" />
       <rect :key="i" x="22" :y="getYPos(i, 3)" rx="3" ry="3" width="200" height="9" />
     </template>