title: Convert async code to promise
body: <p>I use the following code and I need to convert it to promise and at the end return object which contain the file configuration,
  how should I do that ?</p>
  
  <pre><code> var Promise = require('bluebird'),
        glob = promisifyAll(require("glob")),
        fs = Promise.promisifyAll(require("fs"));
  
  module.exports = {
      parse: function (configErr) {
      glob("folder/*.json", function (err, files) {
        if (err) {
          return configErr(new Error("Error to read json files: " + err));
        }
        files.forEach(function (file) {
          fs.readFileAsync(file, 'utf8', function (err, data) { // Read each file
            if (err) {
              return configErr(new Error("Error to read config" + err));
            }
            return JSON.parse(data);
          });
        })
      })
  </code></pre>
  
  <p><strong>UPDATE</strong> -in the code I want to get json files from specific folder in my node project and parse the json content to object  </p>