title: Setting process.env var in package.json
body: <p>I am trying to set and retrieve node app process.env vars using package.json, so by researching the issue, I've found an example to set / retrieve process.env through the 'config' section, so I added a new config section as shown below :</p>
  
  <pre><code>"config" : { "var1" : "test", "var2" : "test2", "var3" : "test3" },
  </code></pre>
  
  <p>But I couldn't access any of the above vars from server.js using for example:</p>
  
  <pre><code>console.log(process.env.npm_package_config_var1); 
  </code></pre>
  
  <p>So I was wondering how I can set / retrieve process.env var using package.json? Thanks</p>
  
  <p>*I am using npm 4.4.1, node 7.4.0 and I run the app using (npm run dev)</p>