Compiling SASS with libsass, Autoprefixer and grunt

Gruntfile.js

module.exports = function (grunt) {
  'use strict';
  
  grunt.loadNpmTasks('grunt-sass');
  grunt.loadNpmTasks('grunt-autoprefixer');

  grunt.initConfig({
    pkg: grunt.file.readJSON('package.json'),
    // Sass
    sass: {
      options: {
        sourceMap: true, // Create source map
        outputStyle: 'compressed' // minify output
      },
      dist: {
        files: [
          {
            expand: true, // Recursive
            cwd: "sass/brand", // The startup directory
            src: ["**/*.scss"], // Source files
            dest: "stylesheets", // Destination
            ext: ".css" // File extension 
          }
        ]
      }
    },

    // Autoprefixer
    autoprefixer: {
      options: {
        browsers: [
          'Android 4',
          'last 2 Chrome version',
          'last 2 iOS version',
          'last 2 Safari version',
          'last 2 ChromeAndroid version',
          'last 2 FirefoxAndroid version',
          'last 2 ExplorerMobile version'
        ],
        map: true // Update source map (creates one if it can't find an existing map)
      },

      // Prefix all files
      multiple_files: {
        flatten: true,
        src: 'stylesheets/**/*.css'
      },
    }
  });

  grunt.registerTask('default', ['sass', 'autoprefixer']);
};

package.json

{
  "name": "MoSite",
  "version": "0.0.1",
  "devDependencies": {
	  "grunt": "0.4.5",		  
	  "grunt-sass": "^0.12.1",
	  "grunt-autoprefixer":  "1.0.0"
	}
}