title: Error while starting Puma server with workers
body: <p>I am new to Rails and Puma, so the issue might be too silly with simple solutions, also please guide me if you think i am doing something wrong.</p>
  
  <p>I am trying to start the Puma server for my rails with the worker. If i set workers to 0 with</p>
  
  <pre><code>puma -w0
  </code></pre>
  
  <p>the server starts perfectly but if i set worker to 1 or more it gives the following error:</p>
  
  <pre><code>E:\RoR_tryouts\ws_13.11.13\todo&gt;puma -w3
  [2120] *** SIGUSR2 not implemented, signal based restart unavailable!
  [2120] *** SIGUSR1 not implemented, signal based restart unavailable!
  [2120] Puma starting in cluster mode...
  [2120] * Version 2.7.1, codename: Earl of Sandwich Partition
  [2120] * Min threads: 0, max threads: 16
  [2120] * Environment: development
  [2120] * Process workers: 3
  [2120] * Phased restart available
  [2120] * Listening on tcp://0.0.0.0:9292
  
  C:/Ruby/Ruby193/lib/ruby/gems/1.9.1/gems/puma-2.7.1/lib/puma/cluster.rb:229:in `trap': unsupported signal SIGCHLD (ArgumentError)
          from C:/Ruby/Ruby193/lib/ruby/gems/1.9.1/gems/puma-2.7.1/lib/puma/cluster.rb:229:in `run'
          from C:/Ruby/Ruby193/lib/ruby/gems/1.9.1/gems/puma-2.7.1/lib/puma/cli.rb:442:in `run'
          from C:/Ruby/Ruby193/lib/ruby/gems/1.9.1/gems/puma-2.7.1/bin/puma:10:in `&lt;top (required)&gt;'
          from C:/Ruby/Ruby193/bin/puma:23:in `load'
          from C:/Ruby/Ruby193/bin/puma:23:in `&lt;main&gt;'
  </code></pre>
  
  <p>Specifications:</p>
  
  <ul>
  <li>Windows 7</li>
  <li>Ruby 1.9.3p448 (2013-06-27) [i386-mingw32] MRI Rail 4.0.0 Puma</li>
  <li>Version 2.7.1, codename: Earl of Sandwich Partition</li>
  </ul>