chore(ngdocs): update lunr to 0.4.0

Author: matsko

bower.json

@@ -2,7 +2,7 @@
   "name": "AngularJS",
   "devDependencies": {
     "jquery": "git://github.com/components/jquery.git#v1.8.3",
-    "lunr.js": "0.3.1",
+    "lunr.js": "0.4.0",
     "google-code-prettify": "1.0.0",
     "components-font-awesome": "3.1.0",
     "bootstrap": "https://raw.github.com/twitter/bootstrap/v2.0.2/docs/assets/bootstrap.zip",