Making a gulpfile: getting an error when call gulp.parallel

I'm working through the book Getting Started With Gulp (which was published in January 2015) but I realize that because development with Gulp is moving quite fast it may be slightly out of date already.

Here is my gulpfile:

// Modules & Plugins
var gulp = require('gulp');
var concat = require('gulp-concat');
var myth = require('gulp-myth');
var uglify = require('gulp-uglify'); // newly added
var jshint = require('gulp-jshint'); // newly added
var imagemin = require('gulp-imagemin');
// let's add two node.js modules:
var connect = require('connect');
// var serve = require('serve-static');
var browsersync = require('browser-sync');
var browserify = require('browserify');
var source = require('vinyl-source-stream');
var plumber = require('gulp-plumber');

// Tasks
// styles task
gulp.task('styles', function(){
    return gulp.src('app/css/*.css')
    // now we add our pipes:
        .pipe(plumber())
        .pipe(concat('all.css'))
        .pipe(myth())
        .pipe(gulp.dest('dist'));
});

// scripts task
gulp.task('scripts', function() {
    return gulp.src('app/js/*.js')
        .pipe(jshint())
        .pipe(jshint.reporter('default'))
        .pipe(concat('all.js'))
        .pipe(uglify())
        .pipe(gulp.dest('dist'));
});

// images task
gulp.task('images', function() {
    return gulp.src('app/img/*')
      .pipe(imagemin())
      .pipe(gulp.dest('dist/img'));
});

// browsersync Task:
gulp.task('browsersync', function(cb) {
    return browsersync({
      server: {
        baseDir:'./'
      }
    }, cb);
});

// browserify Task:
gulp.task('browserify', function() {
    return browserify('./app/js/app.js')
      .bundle()
      .pipe(source('bundle.js'))
      .pipe(gulp.dest('dist'));
});

// watch task:
gulp.task('watch', function() {
  gulp.watch('app/css/*.css',
   gulp.series('styles', browsersync.reload));
  gulp.watch('app/js/*.js',
   gulp.series('scripts', browsersync.reload));
  gulp.watch('app/img/*',
   gulp.series('images', browsersync.reload));
});

// Default Task
gulp.task('default', ['styles', 'scripts', 'images', 'browsersync', 'browserify', 'watch']);

EDIT: After changing the final gulp.task line, it runs but I still get the following error:

[13:51:21] Starting 'watch'...
[13:51:21] 'watch' errored after 146 μs
[13:51:21] TypeError: undefined is not a function
    at Gulp.<anonymous> (/Volumes/BigMan/Code/javascript/gulp-book/gulpfile.js:79:9)
    at module.exports (/Volumes/BigMan/Code/javascript/gulp-book/node_modules/gulp/node_modules/orchestrator/lib/runTask.js:34:7)
    at Gulp.Orchestrator._runTask (/Volumes/BigMan/Code/javascript/gulp-book/node_modules/gulp/node_modules/orchestrator/index.js:273:3)
    at Gulp.Orchestrator._runStep (/Volumes/BigMan/Code/javascript/gulp-book/node_modules/gulp/node_modules/orchestrator/index.js:214:10)
    at Gulp.Orchestrator.start (/Volumes/BigMan/Code/javascript/gulp-book/node_modules/gulp/node_modules/orchestrator/index.js:134:8)
    at /usr/local/lib/node_modules/gulp/bin/gulp.js:129:20
    at process._tickCallback (node.js:355:11)
    at Function.Module.runMain (module.js:503:11)
    at startup (node.js:129:16)
    at node.js:814:3