title: ActiveRecord::Fixture::FixtureError: table "posts" has no column named "user" - where a 'post' belongs_to 'user'
body: <p>I am trying to create some association tests for a class with a <code>belongs_to</code> association.</p>
  
  <p>The test fails when the fixtures are being created - Rails is not detecting the <code>belongs_to :user</code> association in <code>Posts</code>.</p>
  
  <p>It seems to pass in the regular <code>rake test</code> command, but not when the individual file is ran inside <code>guard</code>.</p>
  
  <p>The test is below:</p>
  
  <pre><code>module Post
    class AssociationsTest &lt; ActiveSupport::TestCase
      subject { Post.new }
      should belong_to(:user)
    end
  end
  </code></pre>