title: Rails 3.1.0, geokit, with error acts_as_mappable
body: <p>I am getting the </p>
  
  <pre><code>undefined local variable or method `acts_as_mappable'
  </code></pre>
  
  <p>error when using geokit, and after tons of Goggling and attempts, I cannot seem to be able correct the problem.</p>
  
  <p>Basically, I have the following gems installed:</p>
  
  <pre><code>geokit (1.6.0, 1.5.0)
  geokit-rails31 (0.1.3)
  </code></pre>
  
  <p>and have the following in my model</p>
  
  <pre><code>class House &lt; ActiveRecord::Base
    acts_as_mappable
  end
  </code></pre>
  
  <p>and Gemfile:</p>
  
  <pre><code>gem 'geokit', '&gt;= 1.5.0'
  gem 'geokit-rails31'
  </code></pre>
  
  <p>I get the error with or without doing the following in my local app.</p>
  
  <pre><code>rails plugin install git://github.com/jlecour/geokit-rails3.git
  </code></pre>