[skip ci] Convert img-responsive to img-fluid

app/assets/javascripts/blob/sketch/index.js

@@ -44,7 +44,7 @@ export default class SketchLoader {
     previewLink.href = previewUrl;
     previewLink.target = '_blank';
     previewImage.src = previewUrl;
-    previewImage.className = 'img-responsive';
+    previewImage.className = 'img-fluid';
 
     previewLink.appendChild(previewImage);
     this.container.appendChild(previewLink);

spec/javascripts/blob/sketch/index_spec.js

@@ -82,7 +82,7 @@ describe('Sketch viewer', () => {
       const img = document.querySelector('#js-sketch-viewer img');
 
       expect(img).not.toBeNull();
-      expect(img.classList.contains('img-responsive')).toBeTruthy();
+      expect(img.classList.contains('img-fluid')).toBeTruthy();
     });
 
     it('renders link to image', () => {