Fix error in displaying JStree and revert new default for FactoryBot

app/assets/javascripts/base.js

@@ -29,3 +29,7 @@ $.fn.replaceWithPush = function(a) {
     this.replaceWith($a);
     return $a;
 };
+
+// Disable the use of web workers for JStree due to JS error
+// See https://github.com/vakata/jstree/issues/1717 for details
+$.jstree.defaults.core.worker = false;

spec/support/factory_bot.rb

@@ -0,0 +1,4 @@
+require 'factory_bot'
+
+# Use "old" FactoryBot default to allow auto-creating associations for #build
+FactoryBot.use_parent_strategy = false