title: Reading csv file on s3 in dask
body: <p>I am able to read a csv that's located on s3 in pandas successfully as follows:</p>
  
  <pre><code> pdf=pd.read_csv('s3a:///bucket/input_file.csv')
  </code></pre>
  
  <p>However, if I try to do the same in dask as follows:</p>
  
  <pre><code> ddf=dd.read_csv('s3a:///bucket/input_file.csv')
  </code></pre>
  
  <p>but I get the following error:</p>
  
  <pre><code>&lt;ipython-input-29-07e2d394bb38&gt; in &lt;module&gt;()
  ----&gt; 1 ddf=dd.read_csv('s3a:///bucket/input_file.csv')
  
  /usr/local/anaconda2/lib/python2.7/site-packages/dask/dataframe/io.pyc in read_csv(fn, **kwargs)
   220         return concat([read_csv(f, **kwargs) for f in sorted(glob(fn))])
  221
  --&gt; 222     token = tokenize(os.path.getmtime(fn), kwargs)
  223     name = 'read-csv-%s-%s' % (fn, token)
  224     bom = get_bom(fn, kwargs.get('compression', None))
  
  ...
  
  OSError: [Errno 2] No such file or directory:'s3a:///bucket/input_file.csv'
  </code></pre>
  
  <p>I've also tried using:</p>
  
  <pre><code> ddf=dd.read_csv('s3://bucket/input_file.csv')
  </code></pre>
  
  <p>and get the same error.</p>