title: Webpack CommonsChunkPlugin not working as expected
body: <p>Folder Structure:
  <a href="https://i.stack.imgur.com/Fff9C.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Fff9C.png" alt="Project Folder Structure"></a></p>
  
  <p>app.js, benchmark.js, board.js all require jquery. I just want to extract jquery as vender.js and three other bundles only contain application code:</p>
  
  <p>Webpack Config:</p>
  
  <p><a href="https://i.stack.imgur.com/xizu6.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/xizu6.png" alt="enter image description here"></a></p>
  
  <p>The result is not what I expected:</p>
  
  <p>app.js, benchmark.js, board.js still contains jquery code (as you can see from the huge file size)</p>
  
  <p><a href="https://i.stack.imgur.com/pc3Vz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/pc3Vz.png" alt="Webpack output"></a></p>
  
  <p>Is there anything wrong with my webpack configuration? 
  I just followed the example in :
  <a href="https://github.com/webpack/webpack/tree/master/examples/two-explicit-vendor-chunks" rel="nofollow noreferrer">https://github.com/webpack/webpack/tree/master/examples/two-explicit-vendor-chunks</a>
  <a href="https://github.com/webpack/webpack/tree/master/examples/multiple-entry-points" rel="nofollow noreferrer">https://github.com/webpack/webpack/tree/master/examples/multiple-entry-points</a></p>