Update spec/elasticsearch.jest.ts

Co-authored-by: rozetko <rozetko@corpglory.com>

spec/elasticsearch.jest.ts

@@ -168,7 +168,7 @@ describe('simple query', function(){
   it('check correct time processing', function() {
     let expectedQuery = {
       headers: {
-        "Content-Type": 'application/json'
+        'Content-Type': 'application/json'
       },
       url: datasourse.url,
       method: 'POST',