title: django-compressor is not install with django-shop
body: <p>I cann't install django-compressor with django-shop. It's give an error like this.</p>
  
  <pre><code>Failed building wheel for rcssmin
  =================================
  
  Failed building wheel for rjsmin
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  Command "/home/raisul/Django/Django-Shop/virenv/bin/python3 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-_3410eu4/rcssmin/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /tmp/pip-kau2lsqm-record/install-record.txt --single-version-externally-managed --compile --install-headers /home/raisul/Django/Django-Shop/virenv/include/site/python3.5/rcssmin" failed with error code 1 in /tmp/pip-build-_3410eu4/rcssmin/
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  </code></pre>