Add snapshot test to discussion_jump_to_next_button_spec.js

spec/frontend/notes/components/__snapshots__/discussion_jump_to_next_button_spec.js.snap

+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`JumpToNextDiscussionButton matches the snapshot 1`] = `
+<div
+  class="btn-group"
+  role="group"
+>
+  <button
+    class="btn btn-default discussion-next-btn"
+    data-original-title="Jump to next unresolved discussion"
+    title=""
+  >
+    <icon-stub
+      cssclasses=""
+      name="comment-next"
+      size="16"
+    />
+  </button>
+</div>
+`;

spec/frontend/notes/components/discussion_jump_to_next_button_spec.js

-import jumpToNextDiscussionButton from '~/notes/components/discussion_jump_to_next_button.vue';
+import JumpToNextDiscussionButton from '~/notes/components/discussion_jump_to_next_button.vue';
 import { shallowMount } from '@vue/test-utils';
 
-describe('jumpToNextDiscussionButton', () => {
+describe('JumpToNextDiscussionButton', () => {
   let wrapper;
 
   beforeEach(() => {
-    wrapper = shallowMount(jumpToNextDiscussionButton, {
+    wrapper = shallowMount(JumpToNextDiscussionButton, {
       sync: false,
     });
   });
@@ -14,6 +14,10 @@ describe('jumpToNextDiscussionButton', () => {
     wrapper.destroy();
   });
 
+  it('matches the snapshot', () => {
+    expect(wrapper.vm.$el).toMatchSnapshot();
+  });
+
   it('emits onClick event on button click', () => {
     const button = wrapper.find({ ref: 'button' });