Update indexing event test to use async/await instead of callbacks

Co-Authored-By: James Coglan <9265+jcoglan@users.noreply.github.com>

tests/integration/test.design_docs.js

@@ -96,37 +96,34 @@ adapters.forEach(function (adapter) {
       });
     });
 
-    it('Indexing event', function (done) {
-      var docs1 = [
+    it('Indexing event', async () => {
+      const docs1 = [
         doc,
         {_id: 'dale', score: 3},
         {_id: 'mikeal', score: 5},
         {_id: 'max', score: 4},
         {_id: 'nuno', score: 3},
       ];
-      var db = new PouchDB(dbs.name);
+      let db = new PouchDB(dbs.name);
       // Test invalid if adapter doesnt support mapreduce
       if (!db.query || adapter !== 'local') {
-        return done();
+        return;
       }
 
       let indexingEvents = [];
 
-      db.on('indexing', function (result) {
+      db.on('indexing', (result) => {
         indexingEvents.push(result);
       });
 
-      db.bulkDocs({ docs: docs1 }, function () {
-        db.query('foo/scores', { reduce: false }, function () {          
-          indexingEvents.length.should.equal(2);
-          indexingEvents[0]['indexed_docs'].should.equal(0);
-          indexingEvents[1]['last_seq'].should.equal(5);
-          indexingEvents[1]['results_count'].should.equal(5);
-          indexingEvents[1]['indexed_docs'].should.equal(5);
+      await db.bulkDocs({ docs: docs1 });
+      await db.query('foo/scores', { reduce: false });
 
-          done();
-        });
-      });
+      indexingEvents.length.should.equal(2);
+      indexingEvents[0]['indexed_docs'].should.equal(0);
+      indexingEvents[1]['last_seq'].should.equal(5);
+      indexingEvents[1]['results_count'].should.equal(5);
+      indexingEvents[1]['indexed_docs'].should.equal(5);
     });
 
     it('Concurrent queries', function (done) {