sites/tasks/build-less.js
var gulp = require('gulp');
var less = require('gulp-less');
var autoprefixer = require('gulp-autoprefixer');
gulp.task('build-less', function() {
return gulp.src("./src/less/main.less")
.pipe(less())
.pipe(autoprefixer({cascade: false, browsers: ['last 2 versions']}))
.pipe(gulp.dest('./build/apps/css'));
});