title: Gulpjs combine two tasks into a single task
body: <p>I currently have two tasks, that both compile sass files. I would still like to concat the two directories into separate files but it seems that it would be more maintainable if I could simply create a 'sass' task that would be responsible for all of the sass compilation.</p>
  <pre><code>// Compile Our Sass
  gulp.task('bootstrap-sass', function() {
    return gulp.src('./public/bower/bootstrap-sass/lib/*.scss')
      .pipe(sass())
      .pipe(contcat('bootstrap.css'))
      .pipe(gulp.dest('./public/dist/css'));
  });
  
  gulp.task('site-sass', function() {
    return gulp.src('./public/app/scss/*.scss')
      .pipe(sass())
      .pipe(contcat('site.css'))
      .pipe(gulp.dest('./public/dist/css'));
  });
  </code></pre>
  <p><strong>UPDATE:</strong></p>
  <p>I've tried this:</p>
  <pre><code>// Compile Our Sass
  gulp.task('sass', function() {
    var bootstrap = function() {
      return gulp
        .src('./public/bower/bootstrap-sass/lib/*.scss')
        .pipe(sass())
        .pipe(concat('bootstrap.css'))
        .pipe(gulp.dest('./public/dist/css'));
    };
  
    var site = function() {
      return gulp
        .src('./public/src/scss/*.scss')
        .pipe(sass())
        .pipe(concat('site.css'))
        .pipe(gulp.dest('./public/dist/css'));
    };
  
    return Promise.all([bootstrap, site]);
  });
  </code></pre>
  <p>But now it appears that neither file is being compiled. Any suggestions on what I am doing wrong?</p>