title: Setting default_url_options in test environment doesn't seem to work
body: <p>I've put the following code into my <code>config/environments/test.rb</code> file:</p>
  
  <pre><code>config.action_mailer.default_url_options = { :host =&gt; "localhost:3000" }
  </code></pre>
  
  <p>however when I run my tests, all routes use <code>http://test.host</code>. I'm trying to work with an API that won't accept <code>http://test.host</code> as a valid callback URI, so I need to change this to properly receive the API response. Any idea why this isn't working? (I'm using RSpec, Guard, and Spork in my testing suite).</p>
  
  <p><strong>EDIT</strong>: Possibly relevant - this is being done inside of a controller spec.</p>
  
  <p><strong>EDIT2</strong>: It seems that it changes after a request is made via <code>get</code>, <code>post</code>, etc. Running the following code within the test:</p>
  
  <pre><code>Rails.logger.debug users_url
  get 'http://google.com'
  Rails.logger.debug users_url
  </code></pre>
  
  <p>would produce the following output:</p>
  
  <pre><code>http://localhost:3000/users
  ...get request related response here
  http://google.com/users
  </code></pre>