update vu2

Author: dingyiming

themes/vue/layout/partials/header.ejs

@@ -1,7 +1,7 @@
 <div id="header">
   <a id="logo" href="/">
     <img src="/images/logo.png">
-    <span>Vue.js v2.0.0-rc.8</span>
+    <span>Vue.js v2.0正式版</span>
   </a>
   <span style="
     position: absolute;