title: Gulp4, gulp-imacss and Deprecation Warning
body: <p>I study work with Gulp 4 and use plugin 'gulp-imacss' and other</p>
  
  <pre><code>var imacss = require('gulp-imacss')
  </code></pre>
  
  <p>farther</p>
  
  <pre><code>var imguri = {
          in: source + 'images/inline/*',
          out: source + 'scss/images/',
          filename: '_datauri.scss',
          namespace: 'img'
      }
  </code></pre>
  
  <p>create task that convert images to dataURIs in SCSS source</p>
  
  <pre><code>gulp.task('imguri', function () {
      return gulp.src(imguri.in)
          .pipe(imagemin())
          .pipe(imacss(imguri.filename, imguri.namespace))
          .pipe(gulp.dest(imguri.out))
  });
  </code></pre>
  
  <p>Run <code>gulp imguri</code> in terminal and get:</p>
  
  <blockquote>
    <p>Starting 'imguri'...</p>
    
    <p>(node:90037) [DEP0097] DeprecationWarning: Using a domain property in
    MakeCallback is deprecated. Use the async_context variant of
    MakeCallback or the AsyncResource class instead.</p>
    
    <p>The following tasks did not complete: imguri</p>
    
    <p>Did you forget to signal async completion?</p>
  </blockquote>
  
  <p>I don't understand what to do with the code because of this Deprecation Warning.</p>