Grunt configuration for using autoprefixer with Zurb Foundation

grunt.js

// After some debugging, got this working. Didn't see it documented anywhere so thought I would put this up to help any others
// First install the grunt-postcss and autoprefixer-core npm repositiories
// Looks like this: npm install grunt-postcss autoprefixer-core

var autoprefixer = require('autoprefixer-core');

module.exports = function(grunt) {
  grunt.initConfig({
    pkg: grunt.file.readJSON('package.json'),

    sass: {
      options: {
        includePaths: ['bower_components/foundation/scss']
      },
      dist: {
        options: {
          outputStyle: 'compressed'
        },
        files: {
          'css/app.css': 'scss/app.scss'
        }        
      }
    },
    
    postcss: {
      options: {
        processors: [
          autoprefixer({ browsers: ['last 2 version'] }).postcss
        ]
      },
      dist: { src: 'css/app.css'}
    },

    watch: {
      grunt: { files: ['Gruntfile.js'] },
       postcss: {
          files: 'css/app.css',
          tasks: 'postcss',
          options: {
             nospawn: true
          }
       },
      sass: {
        files: 'scss/**/*.scss',
        tasks: ['sass']
      }
    }
  });

  grunt.loadNpmTasks('grunt-sass');
  grunt.loadNpmTasks('grunt-contrib-watch');
  grunt.loadNpmTasks('grunt-postcss');

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