nit for slower PG test

Author: flovilmart

spec/PushController.spec.js

@@ -716,6 +716,11 @@ describe('PushController', () => {
       var config = new Config(Parse.applicationId);
       return Parse.Object.saveAll(installations).then(() => {
         return pushController.sendPush(payload, {}, config, auth);
+      }).then(() => {
+        // Wait a few ms to let the push be sent
+        return new Promise((resolve) => {
+          setTimeout(resolve, 100);
+        });
       });
     }).then(() => {
       const query = new Parse.Query('_PushStatus');