Fix flaky spec caused by time-dependent snapshot

ee/spec/frontend/analytics/code_review_analytics/components/__snapshots__/merge_request_table_spec.js.snap

@@ -117,7 +117,7 @@ exports[`MergeRequestTable component template matches the snapshot 1`] = `
               </li>
                
               <li>
-                opened 1 month ago
+                opened just now
               </li>
                
               <li>

ee/spec/frontend/analytics/code_review_analytics/components/merge_request_table_spec.js

@@ -59,6 +59,8 @@ describe('MergeRequestTable component', () => {
 
   describe('template', () => {
     beforeEach(() => {
+      jest.spyOn(global, 'Date').mockImplementationOnce(() => new Date('2020-03-09T11:01:58.135Z'));
+
       bootstrap({ mergeRequests });
     });