separate server binding to port from other app config

this seems a bit crude but allows running the tests and having them take
care of setting up the port to use

src/app.ts

@@ -15,7 +15,6 @@ import * as mongoose from "mongoose";
 import * as passport from "passport";
 import expressValidator = require("express-validator");
 
-
 const MongoStore = mongo(session);
 
 /**