title: node_modules dir being included in module published to NPM registry
body: <p>I published my module to the NPM registry. When I installed it using</p>
  
  <pre><code>npm install --save-dev X
  </code></pre>
  
  <p>I see that the node_modules folder was included in the install, such that when I go to project Y which depends on X, I see:</p>
  
  <pre><code>Y/node_modules/X/node_modules
  </code></pre>
  
  <p>How is this possible?</p>
  
  <p>My .npmignore file in my X project is as follows:</p>
  
  <pre><code>.idea
  node_modules
  bower_components
  internal-docs
  </code></pre>
  
  <p>Anyone know what could be up?</p>