refactor: moved sparky from board to pinball

lib/game/components/board.dart

@@ -15,7 +15,6 @@ class Board extends Component {
     final bottomGroup = _BottomGroup();
 
     final flutterForest = FlutterForest();
-    final sparkyFireZone = SparkyFireZone();
 
     // TODO(alestiago): adjust positioning to real design.
     final dino = ChromeDino()
@@ -28,7 +27,6 @@ class Board extends Component {
       bottomGroup,
       dino,
       flutterForest,
-      sparkyFireZone,
     ]);
   }
 }

lib/game/pinball_game.dart

@@ -46,6 +46,7 @@ class PinballGame extends Forge2DGame
     await add(plunger);
 
     unawaited(add(Board()));
+    unawaited(add(SparkyFireZone()));
     unawaited(addFromBlueprint(Slingshots()));
     unawaited(addFromBlueprint(DinoWalls()));
     unawaited(_addBonusWord());

test/game/pinball_game_test.dart

@@ -62,6 +62,17 @@ void main() {
         );
       });
 
+      flameTester.test(
+        'one SparkyFireZone',
+        (game) async {
+          final sparkyFireZone = SparkyFireZone();
+          await game.ready();
+          await game.ensureAdd(sparkyFireZone);
+
+          expect(game.children.whereType<FlutterForest>().length, equals(1));
+        },
+      );
+
       group('controller', () {
         // TODO(alestiago): Write test to be controller agnostic.
         group('listenWhen', () {