gulpfile.js создан после прохождения трех уроков LoftSchool - Таски: 'default',['connect', 'html', 'css', 'watch', 'uncss'

gulpfile.js

"use-strict";

var gulp = require('gulp'),
		concatCss = require('gulp-concat-css'),
		connect = require('gulp-connect'),
		livereload = require('gulp-livereload'),
		minifyCss = require('gulp-minify-css'),
		notify = require('gulp-notify'),
		prefix = require('gulp-autoprefixer'),		
		rename = require('gulp-rename'),
		sass = require('gulp-sass'),
		uncss = require('gulp-uncss');


//connect - https://www.npmjs.com/package/gulp-connect/
gulp.task('connect', function() {
  connect.server({
    root: 'app',
    port: '8080',  // добавил
    livereload: true
  });
});

// uncss -  remove unwanted styles
gulp.task('uncss', function () {
    return gulp.src('bower_components/bootstrap/dist/css/bootstrap.css')
        .pipe(uncss({
            html: ['app/index.html']  //смотрим, какие стили использует html
        }))
        .pipe(gulp.dest('app/css'));
});

// css
gulp.task('css', function () {
  return gulp.src('scss/style.scss')
    .pipe(sass())
    .pipe(prefix({browsers: ['last 2 versions', '> 1%', 'ie 8'], cascade: false}))
    .pipe(minifyCss())
    .pipe(rename('bundle.min.css'))
    .pipe(gulp.dest('app'))
    .pipe(connect.reload());   
});
 
// html
gulp.task('html', function() {
	gulp.src('app/index.html')
	.pipe(connect.reload());
})

gulp.task('watch', function() {
		gulp.watch('css/*.css', ['css'])
		gulp.watch('app/index.html', ['html'])
})

// default
gulp.task('default', ['connect', 'html', 'css', 'watch']);