add note about work in progress to header

Author: chrisvfritz

themes/vue/layout/partials/header.ejs

@@ -1,9 +1,25 @@
 <div id="header">
-    <a id="logo" href="/">
-        <img src="/images/logo.png">
-        <span>Vue.js</span>
-    </a>
-    <ul id="nav">
-        <%- partial('partials/main_menu', { context: 'nav' }) %>
-    </ul>
+  <a id="logo" href="/">
+    <img src="/images/logo.png">
+    <span>Vue.js <sup>2.0 RC</sup></span>
+  </a>
+  <span style="
+    position: absolute;
+    top: 100%;
+    left: 60px;
+    padding: 0 10px;
+    background: #ef9f00;
+    border-radius: 3px;
+    margin-top: -15px;
+    line-height: 30px;
+    color: white;
+    font-weight: bold;
+    letter-spacing: 1px;
+    box-shadow: 0 1px 2px rgba(0,0,0,.3);
+  ">
+    WORK IN PROGRESS
+  </span>
+  <ul id="nav">
+    <%- partial('partials/main_menu', { context: 'nav' }) %>
+  </ul>
 </div>