Style improvements (#2475)

* HooksRouter is enabled by default

* Adds middleswares on PromiseRouter, fixes #2410

* Move testing line to helper

* Modernize middlewares.js

* Moves DB uniqueness initialization to DBController, modernize

* Moves testing related code to spec folder

* remove unused _removeHook function

* Adds tests, docs for Analytics and improvements

* nit

* moves back TestUtils

src/Controllers/AnalyticsController.js

@@ -3,21 +3,23 @@ import { AnalyticsAdapter } from '../Adapters/Analytics/AnalyticsAdapter';
 
 export class AnalyticsController extends AdaptableController {
   appOpened(req) {
-    return this.adapter.appOpened(req.body, req).then(
-      function(response) {
-        return { response: response };
-      }).catch((err) => {
-        return { response: {} };
-      });
+    return Promise.resolve().then(() => {
+      return this.adapter.appOpened(req.body, req);
+    }).then((response) => {
+      return { response: response || {} };
+    }).catch((err) => {
+      return { response: {} };
+    });
   }
 
   trackEvent(req) {
-    return this.adapter.trackEvent(req.params.eventName, req.body, req).then(
-      function(response) {
-        return { response: response };
-      }).catch((err) => {
-        return { response: {} };
-      });
+    return Promise.resolve().then(() => {
+      return this.adapter.trackEvent(req.params.eventName, req.body, req);
+    }).then((response) => {
+      return { response: response || {} };
+    }).catch((err) => {
+      return { response: {} };
+    });
   }
 
   expectedAdapterType() {