Less compilation settings

gruntfile.js

production: {
 options: {
   plugins: [
     require(‘less-plugin-glob’),
     new (require(‘less-plugin-autoprefix’))({
       browsers: [‘> 1%’, ‘last 2 versions’, ‘ie 9’]
     }),
     new (require(‘less-plugin-clean-css’))({
       keepSpecialComments: false,
       processImport: true,
       mediaMerging: true,
       advanced: true
     })
   ]
 },
 files: {
   ‘<%= path.build %>css/style.css’: ‘<%= path.css %>index.less’
 }
}