title: Rails nitrous preview issue with rails 4.2beta
body: <p>After doing git clone for a project I'm working on 
  I updated my rails in nitrous and to Rails 4.2.0.beta2 
  Run
      rails server</p>
  
  <pre><code>=&gt; Booting WEBrick                                                                                                                                                                                                    
  =&gt; Rails 4.2.0.beta2 application starting in development on http://localhost:3000                                                                                                                                     
  =&gt; Run `rails server -h` for more startup options                                                                                                                                                                     
  =&gt; Ctrl-C to shutdown server                                                                                                                                                                                          
  [2014-12-02 20:13:56] INFO  WEBrick 1.3.1                                                                                                                                                                             
  [2014-12-02 20:13:56] INFO  ruby 2.1.4 (2014-10-27) [x86_64-linux]                                                                                                                                                    
  [2014-12-02 20:13:56] INFO  WEBrick::HTTPServer#start: pid=495 port=3000                                                                                                                                              
  ^C[2014-12-02 20:14:48] INFO  going to shutdown ...                                                                                                                                                                   
  [2014-12-02 20:14:48] INFO  WEBrick::HTTPServer#start done.  
  </code></pre>
  
  <p>I go to port 3000 </p>
  
  <pre><code> We couldn't find a server running on this port – are you sure there is a server running?
  Make sure to bind your server to host 0.0.0.0 (instead of localhost/127.0.0.1).
  </code></pre>
  
  <p>What am I doing wrong?    </p>