Allow single server instance in test suite (#7262)

* initial pass

* reconfigureServer when needed

* finish postgres tests

* mongo tests

* more tests

* clean up

* re-add skipped test

* Fix transaction tests

* handle batch

* AuthenticationAdapter fix

* More reconfiguration

* clean up

* properly terminate cli servers

* handle Parse.Push

* Flaky PushController

* ensure reconfigureServer when changed

* fix postgres tests

* remove console.log

* LiveQuery spec remove duplicates and listeners

spec/ParseHooks.spec.js

@@ -15,10 +15,14 @@ const AppCache = require('../lib/cache').AppCache;
 describe('Hooks', () => {
   let server;
   let app;
-  beforeAll(done => {
-    app = express();
-    app.use(bodyParser.json({ type: '*/*' }));
-    server = app.listen(12345, undefined, done);
+  beforeEach(done => {
+    if (!app) {
+      app = express();
+      app.use(bodyParser.json({ type: '*/*' }));
+      server = app.listen(12345, undefined, done);
+    } else {
+      done();
+    }
   });
 
   afterAll(done => {