title: sexmachine reporting None for all lines
body: <p>I'm trying to use sexmachine to identify the genders of names in a pandas DataFrame using the below code:</p>
  
  <pre><code>def gender(n):
      d.get_gender(n)
  df['gender'] = df['first_name'].apply(gender);
  </code></pre>
  
  <p>But every row is "None." </p>
  
  <p>Thanks for any help</p>