Add barebone to support socket.io

(This is more a temp commit to update the frontend)

frontend/src/app/app.module.ts

@@ -14,7 +14,6 @@ import { LoginComponent } from './login/login.component';
 import { MapComponent } from './map/map.component';
 import { UserComponent } from './user/user.component';
 import { DashboardWidgetComponent } from './dashboard-widget/dashboard-widget.component';
-import { MqttModule } from 'ngx-mqtt';
 import { ServiceWorkerModule } from '@angular/service-worker';
 import { environment } from '../environments/environment';
 import { AdminComponent } from './admin/admin.component';
@@ -22,6 +21,8 @@ import { AlertComponent } from './_alert/alert/alert.component';
 import { FontAwesomeModule } from '@fortawesome/angular-fontawesome';
 import { NotificationsComponent } from './notifications/notifications.component';
 
+const config: SocketIoConfig = { url: 'http://localhost:8988', options: {} };
+
 @NgModule({
   declarations: [
     AppComponent,
@@ -42,7 +43,6 @@ import { NotificationsComponent } from './notifications/notifications.component'
     FontAwesomeModule,
     FormsModule,
     HttpClientModule,
-    MqttModule.forRoot({}),
     NgxMapboxGLModule.withConfig({
       accessToken: 'pk.eyJ1IjoibW9uZGVpMSIsImEiOiJja2dsY2ZtaG0xZ2o5MnR0ZWs0Mm82OTBpIn0.NzDWN3P6jJLmci_v3MM1tA'
     }),