Fix Material directives import statement

lib/app_component.dart

@@ -7,9 +7,8 @@ import 'package:rules_of_living/src/Engine.dart';
 @Component(
     selector: 'my-app',
     templateUrl: "app_component.html",
-    directives: [coreDirectives, MaterialIconComponent],
+    directives: [coreDirectives, materialDirectives],
     styleUrls: const ['package:angular_components/app_layout/layout.scss.css'],
-    providers: const [materialProviders],
 )
 class AppComponent implements OnInit {
   var name = "World";