title: How to use mode() on resampling timeseries?
body: <p>I have a dataframe that has timeseries, with each data corresponds to a day_of_week (monday to sunday)</p>
  
  <p>I am interested to know when my timeseries convert to a monthly basis, what's the day_of_week that appears the most frequent for each month and I use the following:</p>
  
  <pre><code>bike['days_of_the_week'].resample('M').mode()
  </code></pre>
  
  <p>But this gave me error </p>
  
  <p>AttributeError: 'DatetimeIndexResampler' object has no attribute 'mode'</p>
  
  <p>So 'mode' doesn't work with timeseries? Then what's the best possible way to figure out the "mode" question after resample?</p>