title: Spork Capybara, config.cache_classes conflict
body: <p>I'm trying to setup Spork and Capybara with TestUnit, and am running 
  into a test.rb config problem.  </p>
  
  <p>The issue is that Spork requires that 
  config.cache_classes be set to false, so that changes in the model can 
  be reflected when running tests without having to reset Spork all the 
  time. </p>
  
  <p>Capybara, on the other hand, seems to require that 
  config.cache_classes be set to true, otherwise the integration tests 
  just don't seem to work. </p>
  
  <p>I'm just looking for any possible solution / explanation for this.  Is 
  this something that only exists within TestUnit, or is this perhaps a 
  bug and I should report it as such?  Any help would be greatly 
  appreciated!</p>