having trouble with this gulp

(original problem) gulpfile.babel.js

var gulp = require('gulp');
var plumber = require('gulp-plumber');
var rename = require('gulp-rename');
var autoPrefixer = require('gulp-autoprefixer');
//if node version is lower than v.0.1.2
//require('es6-promise').polyfill();
var cssComb = require('gulp-csscomb');
var cmq = require('gulp-merge-media-queries');
var cleanCss = require('gulp-clean-css');
var browserify = require('gulp-browserify');
var uglify = require('gulp-uglify');

var browserSync = require('browser-sync').create();
var reload = browserSync.reload

gulp.task('sass',function(){
    gulp.src(['./dev/styles/**/*.scss','./dev/styles/**/*.sass'])
        .pipe(plumber({
            handleError: function (err) {
                console.log(err);
                this.emit('end');
            }
        }))
        .pipe(sourcemaps.init())
        .pipe(sass())
        .pipe(autoPrefixer())
        .pipe(cssComb())
        .pipe(cmq({log:true}))
        .pipe(gulp.dest('build/styles'))
        .pipe(rename({
            suffix: '.min'
        }))
        .pipe(cleanCss())
        .pipe(sourcemaps.write())
        .pipe(gulp.dest('build/styles'))
        .pipe(reload({stream:true}))
});
gulp.task('css',function(){
    gulp.src(['./dev/styles/**/*.css'])
        .pipe(plumber({
            handleError: function (err) {
                console.log(err);
                this.emit('end');
            }
        }))
        .pipe(autoPrefixer())
        .pipe(cssComb())
        .pipe(cmq({log:true}))
        .pipe(gulp.dest('./build/styles'))
        .pipe(rename({
            suffix: '.min'
        }))
        .pipe(cleanCss())
        .pipe(gulp.dest('./build/styles'))
        .pipe(reload())
});
gulp.task('scripts',function(){
    gulp.src(['./dev/scripts/**/*.js'])
        .pipe(plumber({
            handleError: function (err) {
                console.log(err);
                this.emit('end');
            }
        }))
          .pipe(browserify())
        .pipe(gulp.dest('./build/scripts'))
        .pipe(rename({
            suffix: '.min'
        }))
        .pipe(uglify())
        .pipe(gulp.dest('./build/scripts'))
        .pipe(reload())
});
gulp.task('templates',function(){
    gulp.src(['./dev/hypermedia/**/*.html'])
        .pipe(plumber({
            handleError: function (err) {
                console.log(err);
                this.emit('end');
            }
        }))
        .pipe(gulp.dest('./build/hypermedia/'))
        .pipe(reload())
});
gulp.task('html',function(){
    gulp.src(['./**/*.html'])
        .pipe(plumber({
            handleError: function (err) {
                console.log(err);
                this.emit('end');
            }
        }))
        .pipe(gulp.dest('./build/'))
        .pipe(reload())
});
gulp.task('default', function () {
    browserSync.init({
        server: "./build"
    });
    gulp.watch('./dev/scripts/**/*.js',['scripts']);
    gulp.watch('./dev/styles/**/*.css', ['css']);
    gulp.watch(['./dev/styles/**/*.scss','./dev/styles/**/*.sass'],['sass']);
    gulp.watch('./hypermedia/**/*.html', ['templates']);
    gulp.watch('./**/*.html', ['html']);
});

(solution) gulpfile.bable.js

var gulp = require('gulp');
var plumber = require('gulp-plumber');
var rename = require('gulp-rename');
var sourcemaps = require('gulp-sourcemaps');
var sass = require('gulp-sass');
var autoPrefixer = require('gulp-autoprefixer');
//if node version is lower than v.0.1.2
//require('es6-promise').polyfill();
var cssComb = require('gulp-csscomb');
var cmq = require('gulp-merge-media-queries');
var cleanCss = require('gulp-clean-css');
var browserify = require('gulp-browserify');
var uglify = require('gulp-uglify');
var browserSync = require('browser-sync').create();
var reload = browserSync.reload

var clean = require('gulp-clean');
var runSequence = require('run-sequence');

gulp.task('sass', function () {
    return gulp.src(['dev/styles/**/*.scss', 'dev/styles/**/*.sass'])
        .pipe(plumber({
            handleError: function (err) {
                console.log(err);
                this.emit('end');
            }
        }))
        .pipe(sourcemaps.init())
        .pipe(sass())
        .pipe(autoPrefixer())
        .pipe(cssComb())
        .pipe(cmq({ log: true }))
        .pipe(gulp.dest('build/styles'))
        .pipe(rename({
            suffix: '.min'
        }))
        .pipe(cleanCss())
        .pipe(sourcemaps.write())
        .pipe(gulp.dest('build/styles'))
        .pipe(reload({ stream: true }))
});
gulp.task('css', function () {
    return gulp.src(['dev/styles/**/*.css'])
        .pipe(plumber({
            handleError: function (err) {
                console.log(err);
                this.emit('end');
            }
        }))
        .pipe(autoPrefixer())
        .pipe(cssComb())
        .pipe(cmq({ log: true }))
        .pipe(gulp.dest('build/styles'))
        .pipe(rename({
            suffix: '.min'
        }))
        .pipe(cleanCss())
        .pipe(gulp.dest('build/styles'))
        .pipe(reload({ stream: true }))
});
gulp.task('scripts', function () {
    return gulp.src(['dev/scripts/**/*.js'])
        .pipe(plumber({
            handleError: function (err) {
                console.log(err);
                this.emit('end');
            }
        }))
        .pipe(browserify())
        .pipe(gulp.dest('build/scripts'))
        .pipe(rename({
            suffix: '.min'
        }))
        .pipe(uglify())
        .pipe(gulp.dest('build/scripts'))
        .pipe(reload({ stream: true }))
});
gulp.task('templates', function () {
    return gulp.src(['dev/hypermedia/**/*.html'])
        .pipe(plumber({
            handleError: function (err) {
                console.log(err);
                this.emit('end');
            }
        }))
        .pipe(gulp.dest('build/hypermedia/'))
        .pipe(reload({ stream: true }))
});
gulp.task('root', function () {
    return gulp.src(['dev/**/*.html', 'dev/**/*.xml', 'dev/**/*.png', 'dev/**/*.ico'])
        .pipe(plumber({
            handleError: function (err) {
                console.log(err);
                this.emit('end');
            }
        }))
        .pipe(gulp.dest('build/'))
        .pipe(reload({ stream: true }))
});

gulp.task('clean', function () {
    return gulp.src('build/*', { read: false })
        .pipe(clean())
})
gulp.task('watch', function() {
  gulp.watch('dev/scripts/**/*.js', ['scripts']);
  gulp.watch('dev/styles/**/*.css', ['css']);
  gulp.watch(['dev/styles/**/*.scss', 'dev/styles/**/*.sass'], ['sass']);
  gulp.watch('hypermedia/**/*.html', ['templates']);
  gulp.watch(['dev/**/*.html', 'dev/**/*.xml', 'dev/**/*.png', 'dev/**/*.ico'], ['root']);
});
gulp.task('serve', function() {
  browserSync.init({ server: './build/' });
});
gulp.task('default', function(done) {
  runSequence('clean', ['root', 'templates', 'css', 'sass', 'scripts'], 'watch', 'serve', done);
});