title: Getting an error when rounding a series
body: <p>I have a series of floats. It is the results of a data frame sum() operation.
  I need to round all its elements to integer but I get an error:</p>
  
  <pre><code>[in]:
  A= mins.sum().iloc[1:]/60 
  # this line works fine. The .iloc is to get rid of a text column.
  
  [in]:
  print(A)
  
  [out]:
  Min bad                     249.5
  Min pr-ul                   967.57
  intra com diff              178.05
  Intra com diff 60           184.27
  dtype: object
  </code></pre>
  
  <p>Now, if I try to round I get an error:</p>
  
  <pre><code>[in]:
  A.round()
  
  [out]:
  ---------------------------------------------------------------------------
  AttributeError                            Traceback (most recent call last)
  &lt;ipython-input-528-685b5302b717&gt; in &lt;module&gt;()
    3 
    4 print(A)
    ----&gt; 5 A.round()
  
   //anaconda/lib/python3.5/site-packages/pandas/core/series.py in round(self,decimals, *args, **kwargs)
     1303         """
     1304         nv.validate_round(args, kwargs)
     -&gt; 1305         result = _values_from_object(self).round(decimals)
     1306         result = self._constructor(result, index=self.index).__finalize__(self)
     1307 
  
     AttributeError: 'float' object has no attribute 'rint'
  </code></pre>
  
  <p>Can anyone tell me why is that and ho I can fix it?
  I guess that the root of the problem is because the Series is "object" type.
  But what is this? It only contains float numbers!!! it is the results of a data frame summarization</p>
  
  <p>thank you in advance for helping</p>