old_contents: module.exports = {
  
    target: {
      files: [{
        expand: true,
        cwd: '<%= destCSSDir %>' + '/',
        src: '*.css',
        dest: '<%= destCSSDir %>' + '/',
        ext: '.min.css'
      }]
    }
  };
  
new_contents: module.exports = {
    options: {
      sourceMap: true
    },
    target: {
      files: [{
        expand: true,
        cwd: '<%= destCSSDir %>' + '/',
        src: '*.css',
        dest: '<%= destCSSDir %>' + '/',
        ext: '.min.css'
      }]
    }
  };
  
subject: Add source maps support