title: How can you delete a folder and its contents after all tasks have been run in Gulp?
body: <p>Here is what I have now, but it is not working. The css folder is not being cleaned out, but no errors are being thrown.</p>
  
  <pre><code>var gulp = require('gulp');
  var sass = require('gulp-sass');
  var autoprefixer = require('gulp-autoprefixer');
  var concat = require('gulp-concat');
  var minifyCSS = require('gulp-minify-css');
  var del = require('del');
  
  gulp.task('default', ['compile-sass', 'process-css', 'clean-css']);
  
  gulp.task('compile-sass', function () {
      gulp.src('resources/assets/sass/main.scss')
  
          // Compile Sass
          .pipe(sass({
              includePaths: ['resources/assets/bower/foundation/scss/foundation/components/']
          }))
  
          // Autoprefix CSS
          .pipe(autoprefixer({
              browsers: ['last 2 versions'],
              cascade: false
          }))
  
          // Move to Temp Destination
          .pipe(gulp.dest('resources/assets/css'));
  
  });
  
  gulp.task('process-css', ['compile-sass'], function () {
      gulp.src(['resources/assets/css/main.css', 'bower/slick/slick/slick.css'])
  
          // Concat CSS Files
          .pipe(concat('all.min.css'))
  
          // Minify CSS
          .pipe(minifyCSS())
  
          // Move to Final Destination
          .pipe(gulp.dest('public/assets/css/'));
  
  });
  
  gulp.task('clean-css', ['process-css'], function () {
  
      // Delete Temp Files &amp; Folders
      del(['resources/assets/css/']);
  
  });
  </code></pre>