Gulp getting started file for scss compilation and browsersync

Gulpfile.js

// https://www.sitepoint.com/simple-gulpy-workflow-sass/
var gulp = require('gulp');
var sass = require('gulp-sass');
var autoprefixer = require('gulp-autoprefixer');
var sourcemaps = require('gulp-sourcemaps');
var flatten = require('gulp-flatten')
var bs = require('browser-sync').create(); // create a browser sync instance.

var input_scss = './03/**/*.scss';
var input_html = './03/**/*.html';
var output = './03/demos/demos/start/css';
var browsersync_basedir = './03/demos/demos/start/';

var sassOptions = {
    errLogToConsole: true,
    outputStyle: 'expanded'
  };

  var autoprefixerOptions = {
    browsers: ['last 2 versions', '> 5% in DK', 'Firefox ESR']
  };

gulp.task('scss', function () {
  return gulp
    .src(input_scss)
    .pipe(sourcemaps.init())
    .pipe(sass(sassOptions).on('error', sass.logError))
    //.pipe(sourcemaps.write())
    .pipe(autoprefixer(autoprefixerOptions))
    .pipe(flatten())
    .pipe(gulp.dest(output))
    .pipe(bs.reload({stream: true}));
});

// https://scotch.io/tutorials/how-to-use-browsersync-for-faster-development
gulp.task('browser-sync', function() {
    bs.init({
        server: {
            baseDir: browsersync_basedir
        }
    });
});

gulp.task('watch', ['browser-sync'], function () {
    gulp.watch(input_scss, ['scss']);
    gulp.watch(input_html).on('change', bs.reload);
});

// gulp.task('watch', function() {
//     return gulp
//       // Watch the input folder for change,
//       // and run `sass` task when something happens
//       .watch(input, ['sass'])
//       // When there is a change,
//       // log a message in the console
//       .on('change', function(event) {
//         console.log('File ' + event.path + ' was ' + event.type + ', running tasks...');
//       });
//   });

  gulp.task('default', ['watch']);

package.json

{
  "name": "pluralsightrwdlayout",
  "version": "1.0.0",
  "description": "RWD menus",
  "main": "Gulpfile.js",
  "dependencies": {
    "browser-sync": "^2.23.6",
    "bulma": "^0.6.2",
    "gulp": "^3.9.1",
    "gulp-autoprefixer": "^4.1.0",
    "gulp-sass": "^3.1.0",
    "gulp-sourcemaps": "^2.6.4"
  },
  "devDependencies": {
    "gulp-flatten": "^0.4.0"
  },
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "mha",
  "license": "ISC"
}