title: pyyaml is producing undesired !!python/unicode output
body: <p>I am using pyyaml to dump an object to a file. There are several unicode strings in the object. I've done this before, but now it's producing output items like this:</p>
  
  <pre><code>'item': !!python/unicode "some string"
  </code></pre>
  
  <p>Instead of the desired:</p>
  
  <pre><code>'item': 'some string'
  </code></pre>
  
  <p>I'm intending to output as utf-8. The current command I use is:</p>
  
  <pre><code>yaml.dump(data,file(suite_out,'w'),encoding='utf-8',indent=4,allow_unicode=True)
  </code></pre>
  
  <p>In other locations I do the following and it works:</p>
  
  <pre><code>codecs.open(suite_out,"w","utf-8").write(
      yaml.dump(suite,indent=4,width=10000)
  )
  </code></pre>
  
  <p>What am I doing wrong?</p>
  
  <p><em>Python 2.7.3</em></p>