title: gulp-notify: [Error in notifier] Error in plugin 'gulp-notify' not found: notify-send
body: <p>I'm trying to setup Gulp in my install of Laravel 5.1. I've ran then command <code>npm install</code> as specified in the Laravel documentation and that's worked fine.</p>
  
  <p>However, when I now run the command <code>gulp</code> I get the following message:</p>
  
  <pre><code>ubuntu@NAME:/var/www/html/FOLDER# gulp
  [14:04:56] Using gulpfile /var/www/html/FOLDER/gulpfile.js
  [14:04:56] Starting 'default'...
  [14:04:56] Starting 'sass'...
  [14:04:56] Running Sass: resources/assets/sass/app.scss
  [14:04:56] Finished 'default' after 532 ms
  [14:04:56] gulp-notify: [Laravel Elixir] Sass Compiled!
  [14:04:56] Finished 'sass' after 666 ms
  [14:04:56] gulp-notify: [Error in notifier] Error in plugin 'gulp-notify'
  not found: notify-send
  </code></pre>
  
  <p>Has anyone else encountered the error?</p>
  
  <pre><code>gulp-notify: [Error in notifier] Error in plugin 'gulp-notify'
  not found: notify-send
  </code></pre>
  
  <p>Thanks</p>