title: PyLint not recognizing cv2 members
body: <p>I am running pylint on an opencv project and I am getting many pylint errors in VS code about  members not being present.</p>
  
  <p>Example code:</p>
  
  <pre><code>import cv2
  cv2.imshow(....)
  </code></pre>
  
  <p>Errors obtained: </p>
  
  <p><a href="https://i.stack.imgur.com/4Kbdh.png" rel="noreferrer"><img src="https://i.stack.imgur.com/4Kbdh.png" alt="enter image description here"></a></p>
  
  <p>However , the code runs correctly without any errors.</p>
  
  <p>Versions : pylint 1.8.1 , astroid 1.6.0</p>