title: Having a default port when running tests in ruby on rails
body: <p>Im trying to run my tests with
  <code>rake spec</code> 
  Im using rspec,capybara with selenium as webdriver. The problem is when ever I try to run the specs It starts up the testing environment in a different port every time. I don't want this to happen as it messes up my Facebook login. 
  How would I make the environment start in the same port every time.
  pls help!</p>