title: BackgroundSubtractionGMG cannot running in Open CV 3.0
body: <p>I have been trying a background subtraction in new Open CV release, Open CV 3.0. I practice a BackgroundSubtractorGMG in Open CV 3.0 and python 2.7. I trying a code at this <a href="http://opencv-python-tutroals.readthedocs.org/en/latest/py_tutorials/py_video/py_bg_subtraction/py_bg_subtraction.html" rel="nofollow">BackgroundSubtractorGMG</a>. The error says:</p>
  
  <blockquote>
    <p>File "background.py", line 10, in  fgbg = cv2.createBackgroundSubtractorGMG() AttributeError: 'module' object has no attribute 'createBackgroundSubtractorGMG'</p>
  </blockquote>
  
  <p>how do I solve this error? I appreciate for your attention and for the help thank you :-) </p>