title: example not working - bind.cols using plyrmr
body: <p>Why does this simple block of code not work using <a href="https://github.com/RevolutionAnalytics/plyrmr" rel="nofollow"><code>plyrmr</code></a>?</p>
  
  <pre><code>input(mtcars) %|%
    group(gear) %|%
    bind.cols(obs = seq(from=1,to=nrow())) 
  </code></pre>
  
  <p>The error I get is:</p>
  
  <pre><code>Error: java.lang.RuntimeException: PipeMapRed.waitOutputThreads(): subprocess failed with code 1
  </code></pre>