generate pngs from all psds in a folder with grunt

Gruntfile.js

module.exports = function(grunt) {

  grunt.initConfig({
    pkg: grunt.file.readJSON('package.json'),

    'convertPSD': {

        target: { prop1:1 },

        options: {
          defProperty: "defValue",
          dFiles: { 
            cwd: './',   
            src: ['*.psd'], 
            dest: './'  

          }
        }
    }

  });



  grunt.registerTask('default', 'convertPSD');
  
  grunt.registerMultiTask('convertPSD', 'Convert PSDs', function() {
    var done = this.async();
    
    var curTask = this,
        opts = curTask.options();

    if (!curTask.files.length && 'dFiles' in opts) {
      var df = opts.dFiles;

      curTask.files = grunt.file.expandMapping(df.src, df.dest , df);

    }

this.files.forEach(function(file){

      console.log(file.src[0])
      var psdFile = file.src[0];


      grunt.util.spawn({
        cmd:'./ImageMagick/convert.exe',
        args:[psdFile + '[0]', psdFile + '.png']
      }, function(error, result, code){
        console.log(error);
        console.log(result);
        console.log(code);
        done();
      })

    
       
})


});


};