如何使用Gulp.js将流保存到多个目的地?

var gulp = require('gulp');
var $ = require('gulp-load-plugins')();
var source = require('vinyl-source-stream');
var browserify = require('browserify');

gulp.task('scripts', function () {
  return browserify('./src/app.js').bundle()
    .pipe(source('app.js'))
    .pipe(gulp.dest('./build'))       // OK. app.js is saved.
    .pipe($.rename('app.min.js'))
    .pipe($.streamify($.uglify())
    .pipe(gulp.dest('./build'));      // Fail. app.min.js is not saved.
});
var gulp = require('gulp');
var $ = require('gu