Use webpack to deliver jstree (and use newest version)

Also delete bootstrap files now served via webpack

app/assets/javascripts/application.js

@@ -22,7 +22,6 @@
 // vendor/assets
 //= require ace/ace
 //= require ace/ext-language_tools
-//= require jstree/jstree.min
 //= require jquery-ui.min
 //= require underscore.min
 //= require_tree .

app/assets/stylesheets/application.css

@@ -20,6 +20,5 @@
  *= require google_opensans
  *= require jquery-ui.min
  *= require jquery-ui.structure.min
- *= require style.min
  *= require_tree .
 */

app/javascript/packs/application.js

@@ -11,6 +11,8 @@
 import 'jquery'
 import 'bootstrap/dist/js/bootstrap.bundle.min';
 import 'chosen-js/chosen.jquery';
+import 'jstree';
 
 // CSS
 import 'chosen-js/chosen.css';
+import 'jstree/dist/themes/default/style.min.css';