title: undefined method `create_translation_table!'
body: <p>I have a new rails engine and I want to use globalize3. I did this in my lib//engine.rb :</p>
  
  <pre><code>require 'globalize3'
  
  module SimpleCms
    class Engine &lt; ::Rails::Engine
    end
  end
  </code></pre>
  
  <p>Now, I try to create a migration like this :</p>
  
  <pre><code>class CreatePages &lt; ActiveRecord::Migration
    def up
      create_table :pages do |t|
        t.string :path
        t.timestamps
      end
      Page.create_translation_table! title: :string, body: :body
    end
  
    def down
      drop_table :pages
      Page.drop_translation_table!
    end
  end
  </code></pre>
  
  <p>And I have this error :</p>
  
  <pre><code>undefined method `create_translation_table!' for #&lt;Class:0x00000001d5ca18&gt;
  </code></pre>
  
  <p>I think the file 'lib/globalize/active_record/migration.rb' is not loaded.</p>
  
  <p>Any solution?</p>