Fix update attributes ( close #90) (#91)

* improve example for testing updateAttribtutes

* Fix updateAttributes bug

(Fix #90)
* change `utils/extractAttributes` to generate a vnode-compatible data object
* remove `utils/updateAttributes` method and references in hooks and methods
* make `this.attributes` return an empty object by default
* fix `noWrapper` computed prop which relied in `!this.attributes`
* fix render function to spread `this.attributes` it onto the root element

* 1.2.1-beta.1

* bump version

example/index.html

@@ -14,7 +14,7 @@ <h4>The following content is outside of the control of the Vue main instance</h4
     <p>But we can render stuff here nonetheless with the <i>mountTarget</i> Prop</p>
     <div class="wrapper">
       <div class="item destination">
-        <div id="external-target" class="test-external-target">
+        <div id="external-target" class="test-external-target" style="border: 1px solid grey;">
         </div>
       </div>
     </div>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "portal-vue",
-  "version": "1.2.0",
+  "version": "1.2.1",
   "description": "A Vue component to render elements outside of a component's template, elsewhere in the DOM",
   "main": "dist/portal-vue.js",
   "files": [