transitionally downgraded to Rails 4.1 since activerecord-jdbcpostgresql-adapter is not fully compatible with Active Record 4.2

config/application.rb

@@ -1,6 +1,13 @@
 require File.expand_path('../boot', __FILE__)
 
-require 'rails/all'
+# Pick the frameworks you want:
+require "active_model/railtie"
+require "active_record/railtie"
+require "action_controller/railtie"
+require "action_mailer/railtie"
+require "action_view/railtie"
+require "sprockets/railtie"
+# require "rails/test_unit/railtie"
 
 # Require the gems listed in Gemfile, including any gems
 # you've limited to :test, :development, or :production.
@@ -21,9 +28,6 @@ module CodeOcean
     # config.i18n.default_locale = :de
     config.i18n.available_locales = [:de, :en]
 
-    # Do not swallow errors in after_commit/after_rollback callbacks.
-    config.active_record.raise_in_transactional_callbacks = true
-
     config.autoload_paths << Rails.root.join('lib')
     config.eager_load_paths << Rails.root.join('lib')
   end