title: convert dask series into dask dataframe
body: <p>I would like to know how to convert a <code>dask.dataframe.core.Series</code> to a dask dataframe. </p>
  
  <p>I have:</p>
  
  <p><code>type(card_id_pur_freq)</code></p>
  
  <p>output:</p>
  
  <p><code>dask.dataframe.core.Series</code></p>
  
  <p>I tried:</p>
  
  <p><code>card_id_pur_freq = dd.DataFrame(card_id_pur_freq)</code></p>
  
  <p>output:</p>
  
  <pre><code>---------------------------------------------------------------------------
  TypeError                                 Traceback (most recent call last)
  &lt;ipython-input-36-bd6cdab52455&gt; in &lt;module&gt;
  ----&gt; 1 card_id_pur_freq = dd.DataFrame(card_id_pur_freq)
  
  TypeError: __init__() missing 3 required positional arguments: 'name', 'meta', and 'divisions'
  </code></pre>
  
  <p>I would like to know how to convert a dask series into a dataframe.</p>
  
  <p>Please let me know. @MRocklin</p>
  
  <p>Thanks</p>
  
  <p>Michael</p>