title: Gulp + babelify + browserify issue
body: <p>I'm trying to create a gulp task with browserify and babelify. Here is the task:</p>
  
  <pre><code>var gulp = require('gulp');
  var browserify = require('gulp-browserify');
  var source = require('vinyl-source-stream');
  var babelify = require('babelify');
  
  gulp.task('js', function () {
      browserify('./resources/js/*.js')
          .transform(babelify)
          .bundle()
          .pipe(source('*.js'))
          .pipe(gulp.dest('./public/js'));
  });
  </code></pre>
  
  <p>I found a few sample code, tried to use them, but the result was always the same.</p>
  
  <p>When i run the task, and save my example.js file, the following error occurs:</p>
  
  <p><code>TypeError: browserify(...).transform is not a function</code></p>
  
  <p>What am I doing wrong?</p>