title: NodeJS unsafe-perm not working on package.json
body: <p>I'm trying to run a <code>npm install</code> command with a preinstall script at my <code>package.json</code>. I know it's antipattern but I need to run some scripts as root.</p>
  
  <p>It's working fine by adding a <code>.npmrc</code> file containing <code>unsafe-perm = true</code> to my root directory. But it's not working by add a config property in my <code>package.json</code> file:</p>
  
  <pre><code>   {
       "name": "foo",
       "version": "1.4.4",
       "config": {
          "unsafe-perm":true
       },
       "scripts" :  { 
          "preinstall" : "npm install -g bower"
       }
     }
     // It is not working
  </code></pre>
  
  <p>According with <a href="https://docs.npmjs.com/misc/config#unsafe-perm" rel="noreferrer">NPM config docs</a> it's ok adding this property in my package file. I want to understand why it's not working. </p>