Grunt Setup

Gruntfile.js

module.exports = function(grunt) {

    grunt.initConfig({
        shell: {
            myth: {
                command: function() {
                    return 'myth css/myth/input.css css/style.css';
                },
                options: {
                    stdout: true,
                    stderr: true,
                    failOnError: true
                }
            }
        },
        cssmin: {
            banner: {
                options: {
                    banner: '/* Generated using Myth.io Processor */'
                },
                files: {
                    'css/style.min.css': ['css/style.css']
                }
            }
        },
        notify: {
            buildcss: {
                options: {
                    message: 'CSS build is completed'
                }
            }
        },
        watch: {
            options: {
                livereload: true
            },
            css: {
                files: ['css/myth/*.css'],
                tasks: ['shell', 'cssmin', 'notify:buildcss']
            }
        }
    });

    grunt.loadNpmTasks('grunt-shell');
    grunt.loadNpmTasks('grunt-contrib-cssmin');
    grunt.loadNpmTasks('grunt-contrib-watch');
    grunt.loadNpmTasks('grunt-notify');
    grunt.registerTask('default', ['watch']);

}

package.json

{
  "name": "WorldOfHerbs",
  "version": "2.0.0",
  "devDependencies": {
    "grunt": "~0.4.2",
    "grunt-shell": "~0.6.1",
    "grunt-contrib-cssmin": "~0.7.0",
    "grunt-contrib-watch": "~0.5.3",
    "grunt-notify": "~0.2.16"
  }
}