title: Meteor Not Excluding Node Modules in the Private Folder?
body: <p>I'm adding my own grunt build setup to my meteor project and assumed from the docs that if I put it into the private folder, it would be left alone by iso-build.  Alas this is not the case, and all manner of hell breaks loose.  </p>
  
  <p>I'd like to know why?</p>
  
  <p>A simple solution is to put my assets folder outside the meteor folder, which I'm fine with.</p>
  
  <p><strong>NB :</strong> I'm not looking to debate the validity using grunt in this situation, I'm interesting in understanding how iso-build treats folders, and how, if possible, to implement some control over what it includes or ignores etc.</p>