title: Error when running rails server
body: <p>I am trying to configure declarative authorization to my rails blog app. After doing all as required, I did rails s to start the server. I have got stuck with the following error.</p>
  
  <pre><code>rails s
  /var/lib/gems/1.8/gems/activerecord-3.2.9/lib/active_record/dynamic_matchers.rb:50:in `method_missing': undefined local variable or method `scopes' for ActiveRecord::Base:Class (NameError)
      from /var/lib/gems/1.8/gems/declarative_authorization-0.5.2/lib/declarative_authorization/in_model.rb:37:in `included'
      from /var/lib/gems/1.8/gems/declarative_authorization-0.5.2/lib/declarative_authorization/in_model.rb:36:in `module_eval'
      from /var/lib/gems/1.8/gems/declarative_authorization-0.5.2/lib/declarative_authorization/in_model.rb:36:in `included'
      from /var/lib/gems/1.8/gems/declarative_authorization-0.5.2/lib/declarative_authorization.rb:17:in `include'
      from /var/lib/gems/1.8/gems/declarative_authorization-0.5.2/lib/declarative_authorization.rb:17:in `send'
      from /var/lib/gems/1.8/gems/declarative_authorization-0.5.2/lib/declarative_authorization.rb:17
      from /var/lib/gems/1.8/gems/bundler-1.2.3/lib/bundler/runtime.rb:68:in `require'
      from /var/lib/gems/1.8/gems/bundler-1.2.3/lib/bundler/runtime.rb:68:in `require'
      from /var/lib/gems/1.8/gems/bundler-1.2.3/lib/bundler/runtime.rb:66:in `each'
      from /var/lib/gems/1.8/gems/bundler-1.2.3/lib/bundler/runtime.rb:66:in `require'
      from /var/lib/gems/1.8/gems/bundler-1.2.3/lib/bundler/runtime.rb:55:in `each'
      from /var/lib/gems/1.8/gems/bundler-1.2.3/lib/bundler/runtime.rb:55:in `require'
      from /var/lib/gems/1.8/gems/bundler-1.2.3/lib/bundler.rb:128:in `require'
      from /blogging/config/application.rb:7
      from /var/lib/gems/1.8/gems/railties-3.2.9/lib/rails/commands.rb:53:in `require'
      from /var/lib/gems/1.8/gems/railties-3.2.9/lib/rails/commands.rb:53
      from /var/lib/gems/1.8/gems/railties-3.2.9/lib/rails/commands.rb:50:in `tap'
      from /var/lib/gems/1.8/gems/railties-3.2.9/lib/rails/commands.rb:50
      from script/rails:6:in `require'
      from script/rails:6
  </code></pre>
  
  <p>My blog app is somewhat similar to this <a href="https://github.com/railscasts/188-declarative-authorization/tree/master/blog" rel="nofollow">blog</a> app.</p>
  
  <p>Kindly help to resolve this issue. Thanks. :)-</p>