title: run-sequence doesn't run gulp tasks in order
body: <p>I have 3 tasks in my Gulp file that must run in this order:</p>
  
  <ol>
  <li><code>clean</code> (deletes everything in the <code>/dist</code> folder)</li>
  <li><code>copy</code> (copies multiple files into the <code>/dist</code> folder)</li>
  <li><code>replace</code> (replaces some strings in some files in the <code>/dist</code> folder)</li>
  </ol>
  
  <p>I've read all the other posts, I've tried "run-sequence" but it's not working as the "replace" task isn't running last.  I'm confused by the use of "callback".  Running the tasks individually works fine.</p>
  
  <pre><code>var gulp = require('gulp');
  var runSequence = require('run-sequence');
  
  gulp.task('runEverything', function(callback) {
      runSequence('clean',
                  'copy',
                  'replace',
                  callback);
  });
  
  gulp.task('clean', function () {
      return del(
          'dist/**/*'
      );
  });
  
  gulp.task('copy', function() {
      gulp.src('node_modules/bootstrap/dist/**/*')
          .pipe(gulp.dest('dist/vendor'))
      //...
      return gulp.src(['index.html', '404.html', '.htaccess'])
          .pipe(gulp.dest('dist/'));
  });
  
  gulp.task('replace', function(){
      gulp.src(['dist/index.php', 'dist/info.php'])
          .pipe(replace('fakedomain.com', 'realdomain.com'))
          .pipe(gulp.dest('dist'));
  
      return gulp.src(['dist/config.php'])
          .pipe(replace('foo', 'bar'))
          .pipe(gulp.dest('dist'));
  });
  </code></pre>
  
  <p>A full example using these 3 tasks would be appreciated.  Thank you.</p>