gulp for es6 -> all-browser-friendly

gulp.es6.sample.js

// change es6 to all-browser-friendly js

var gulp = require('gulp');
var sourcemaps = require('gulp-sourcemaps');
var plumber = require('gulp-plumber');
var babel = require('gulp-babel');

gulp.task('js', ['clean:js'], function() {
    return gulp.src('dev/**/*.js') // input files
        .pipe(sourcemaps.init()) // help to show where error is init
        .pipe(plumber()) // fix gulp pipe
        .pipe(babel({
            presets: ['es2015'] // change to es5
        }))
        .pipe(concat('bundle.min.js'))
        .pipe(sourcemaps.write())
        .pipe(gulp.dest('.')); // output files
});