Add app entry point

ExpressAPI/src/app.ts

+// Read from the .env file
+// ATTENTION : This line MUST be the first of this file
+require('dotenv').config();
+
+import WorkerRole     from './process/WorkerRole';
+import ClusterManager from './process/ClusterManager';
+import API            from './express/API';
+
+
+(new ClusterManager([ {
+    role         : WorkerRole.API,
+    quantity     : ClusterManager.CORES,
+    restartOnFail: true,
+    loadTask     : () => {
+        return new API();
+    }
+} ])).run();