chore(build): update Bootstrap dependency

* Update the Bootstrap version used by the Plunker demos.

Closes angular-ui#4865

Author: icfantv

Diff for: Gruntfile.js

@@ -9,7 +9,7 @@ module.exports = function(grunt) {
 
   grunt.initConfig({
     ngversion: '1.4.7',
-    bsversion: '3.1.1',
+    bsversion: '3.3.5',
     modules: [],//to be filled in by build task
     pkg: grunt.file.readJSON('package.json'),
     dist: 'dist',