title: imread_collection There is no item
body: <p>I am trying to read several images from archive with <a href="http://scikit-image.org/docs/dev/api/skimage.io.html#skimage.io.imread_collection" rel="nofollow noreferrer">skimage.io.imread_collection</a>, but for some reason it throws an error:</p>
  
  <blockquote>
    <p>"There is no item named '00071198d059ba7f5914a526d124d28e6d010c92466da21d4a04cd5413362552/masks/*.png' in the archive".</p>
  </blockquote>
  
  <p>I checked several times, such directory exists in archive and with *.png I just specify that I want to have all images in my collection, and <code>imread_collection</code> works well, when I am trying to download images not from archive, but from extracted folder.</p>
  
  <pre><code>#specify folder name
  each_img_idx = '00071198d059ba7f5914a526d124d28e6d010c92466da21d4a04cd5413362552'
  
  with zipfile.ZipFile('stage1_train.zip') as archive:
      mask_ = skimage.io.imread_collection(archive.open(str(each_img_idx) + '/masks/*.png')).concatenate() 
  </code></pre>
  
  <p>May some one explain me, what's going on?</p>