The testimonials are title blocks and images of the stars that are found in app > img-assets > rating-4.png

The code for it is located in index.html under the .hg-reviews section.

<div class="col-md-12 col-sm-12">
   <div class="clearfix hg-title-block">
    <h3 class="hg-title-block__title">Gunter</h3>
    <h4 class="hg-title-block__subtitle">Thanks once more for the good time in your lovely apartment, which we enjoyed very much! It was very comfortable, clean and equipped with love. You helped us a lot with your tips! The buss station is very near and it was easy to find and go to all destinations by buss.</h4>
   </div>
  <div class="hg-testimonialSlider--image-boxes">
    <img class="hg-testimonialSlider--image-boxes__element img-responsive" src="img-assets/rating-5.png" alt="rating5" >
  </div>
</div>

The class that triggers the slick slider is .hg-testimonialSlider

The style of the testimonials is found in app/style/scss/_testimonialSlider.scss