title: factory_girl + rspec doesn't seem to roll back changes after each example
body: <p>Similar to the problem described here:
  <a href="http://rpheath.com/posts/411-how-to-use-factory-girl-with-rspec" rel="noreferrer">http://rpheath.com/posts/411-how-to-use-factory-girl-with-rspec</a></p>
  
  <p>in Short (shorten'd code):</p>
  
  <p>spec_helper:</p>
  
  <pre><code>config.use_transactional_fixtures = true
  config.use_instantiated_fixtures  = false
  </code></pre>
  
  <p>factories.rb:</p>
  
  <pre><code>Factory.define :state do
    f.name "NY"
  end
  </code></pre>
  
  <p>in my spec</p>
  
  <pre><code>before(:each) do 
    @static_model = Factory(:state) # with validate uniqueness of state name
  end
  </code></pre>
  
  <p>error:</p>
  
  <blockquote>
    <p>duplicate entry name "NY" etc.</p>
  </blockquote>
  
  <hr>
  
  <p><strong>Question:
  Shouldn't rspec clear database before each spec example and hence not throwing duplicate entry errors?</strong></p>