title: when using OmniAuth in rails application why I always met Errno::ETIMEDOUT
body: <p>I have a rails dummy application, And I've add OmniAuth into my Gemfile.
  I've add</p>
  
  <pre><code>&lt;%= link_to "Sign in with Twitter", "/auth/twitter" %&gt;
  </code></pre>
  
  <p>in my application layout file.</p>
  
  <p>Also I've add the omniauth.rb file in my config\initializers folder.</p>
  
  <pre><code>Rails.application.config.middleware.use OmniAuth::Builder do
    provider :twitter, 'MYKEY', 'MYSECERT'
  end
  </code></pre>
  
  <p>After I restart of my rails server with <code>rails s</code> and visit <a href="http://localhost:3000/auth/twitter" rel="nofollow">http://localhost:3000/auth/twitter</a></p>
  
  <p>I've always met <code>Errno::ETIMEDOUT</code>, saying <code>Operation timed out - connect(2)</code></p>
  
  <p>My computer can visit Twitter website meanwhile.</p>
  
  <p>Can anyone help me what was going wrong here? Thank you very much.</p>