Remove moot `version` property from bower.json

Per bower/bower.json-spec@a325da3

bower.json

@@ -1,6 +1,5 @@
 {
   "name": "vue",
-  "version": "0.12.0-rc2",
   "main": "dist/vue.js",
   "description": "Simple, Fast & Composable MVVM for building interative interfaces",
   "authors": ["Evan You <yyx990803@gmail.com>"],
@@ -14,4 +13,4 @@
     "*.json",
     "*.md"
   ]
-}
+}