title: Bundler could not find compatible versions for gem "activerecord"
body: <p>I am trying to install acts_as_commentable_with_threading. I have added "gem 'acts_as_commentable_with_threading'" to my Gemfile.</p>
  
  <p>When I run "bundle install" from the command line I get the following.</p>
  
  <pre><code>Fetching source index for http://rubygems.org/
  Bundler could not find compatible versions for gem "activerecord":
    In Gemfile:
      acts_as_commentable_with_threading depends on
        activerecord (~&gt; 3.0.0)
  
      rails (= 3.1.0) depends on
        activerecord (3.1.0)
  </code></pre>
  
  <p>So acts_as_commentable_with_threading won't work with activerecord 3.1.0? I am not sure how to workaround this?</p>
  
  <p>Thanks</p>