title: command gulp error "assert.js:42 throw new errors.AssertionError"
body: <p>I have a simple install gulp livereload:</p>
  
  <p>gulp
  assert.js:42
    throw new errors.AssertionError({
    ^</p>
  
  <p>AssertionError [ERR_ASSERTION]: Task function must be specified
      at Gulp.set [as _setTask] (c:\testjses6\node_modules\undertaker\lib\set-task.js:10:3)
      at Gulp.task (c:\testjses6\node_modules\undertaker\lib\task.js:13:8)
      at Object. (c:\testjses6\gulpfile.js:21:6)
      at Module._compile (module.js:652:30)
      at Object.Module._extensions..js (module.js:663:10)
      at Module.load (module.js:565:32)
      at tryModuleLoad (module.js:505:12)
      at Function.Module._load (module.js:497:3)
      at Module.require (module.js:596:17)
      at require (internal/module.js:11:18)</p>