Rails 5/PaperTrail/belongs_to_required_by_default issue

bug.rb

# Failing test for versioning destroyed objects using PaperTrail and Rails 5 (with new AR default config option)
begin
  require 'bundler/inline'
rescue LoadError => e
  $stderr.puts 'Bundler version 1.10 or later is required. Please update your Bundler'
  raise e
end

gemfile(true) do
  ruby '2.3.0'
  source 'https://rubygems.org'
  gem 'activerecord', '5.0.0.beta1'
  gem 'minitest', '5.8.3'
  gem 'paper_trail', '4.0.1', require: false
  gem 'sqlite3'
end

require 'active_record'
require 'minitest/autorun'
require 'logger'
ActiveRecord::Base.belongs_to_required_by_default = true
ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: ':memory:')
ActiveRecord::Base.logger = Logger.new(STDOUT)
require 'paper_trail'

ActiveRecord::Schema.define do
  create_table :users, force: true do |t|
    t.text :first_name, null: false
    t.timestamps null: false
  end
  create_table :versions do |t|
    t.string :item_type, null: false
    t.integer :item_id, null: false
    t.string :event, null: false
    t.string :whodunnit
    t.text :object, limit: 1_073_741_823
    t.text :object_changes, limit: 1_073_741_823
    t.integer :transaction_id
    t.datetime :created_at
  end
  add_index :versions, [:item_type, :item_id]
  add_index :versions, [:transaction_id]

  create_table :version_associations do |t|
    t.integer  :version_id
    t.string   :foreign_key_name, null: false
    t.integer  :foreign_key_id
  end
  add_index :version_associations, [:version_id]
  add_index :version_associations, [:foreign_key_name, :foreign_key_id],
    name: 'index_version_associations_on_foreign_key'
end

class User < ActiveRecord::Base
  has_paper_trail
end

class BugTest < ActiveSupport::TestCase
  def test_1
    @j = User.create(first_name: "Jane")
    assert_difference(-> { PaperTrail::Version.count }, +1) {
      @j.destroy
    }
  end
end