title: imdbpy rating data missing
body: <p><br/>
  i have a question about the <a href="http://imdbpy.sourceforge.net/index.html" rel="nofollow">imdbpy</a> module for python, for some reason i can't retrieve some data about tv shows even though they exist on the imdb.com website.<br/>
  for example if i use this code:</p>
  
  <pre><code>from imdb import IMDb
  i = IMDb()
  s = i.search_movie('killjoys')
  m = i.get_movie(s[0].movieID)
  print m.get('rating') 
  </code></pre>
  
  <p>the result is <strong>None</strong> even though on the <a href="http://imdb.com" rel="nofollow">imdb.com</a> it's available
  so what should i so here? and thanks for the help :)</p>