Updating gemspec for Rails 4.0 and remove depricated mass assignment

Gemfile

@@ -1,2 +1,5 @@
 source :rubygems
+
+gem 'rails',     github: 'rails/rails'
+
 gemspec

lib/paper_trail/version.rb

@@ -1,7 +1,6 @@
 class Version < ActiveRecord::Base
   belongs_to :item, :polymorphic => true
   validates_presence_of :event
-  attr_accessible :item_type, :item_id, :event, :whodunnit, :object, :object_changes
 
   def self.with_item_keys(item_type, item_id)
     scoped(:conditions => { :item_type => item_type, :item_id => item_id })

paper_trail.gemspec

@@ -15,8 +15,8 @@ Gem::Specification.new do |s|
   s.executables   = `git ls-files -- bin/*`.split("\n").map{ |f| File.basename(f) }
   s.require_paths = ['lib']
 
-  s.add_dependency 'railties', '~> 3.0'
-  s.add_dependency 'activerecord', '~> 3.0'
+  s.add_dependency 'railties', '~> 4.0.0.beta'
+  s.add_dependency 'activerecord', '~> 4.0.0.beta'
 
   s.add_development_dependency 'rake'
   s.add_development_dependency 'shoulda', '~> 3.3'

test/dummy/config/initializers/paper_trail.rb

@@ -1,3 +1,2 @@
 class Version < ActiveRecord::Base
-  attr_accessible :created_at, :updated_at, :answer, :action, :question, :article_id, :ip, :user_agent, :title
 end