wip: bloc for holidays

lib/api/holidays/getHolidays.dart

@@ -1,5 +1,4 @@
 import 'dart:convert';
-
 import 'package:http/http.dart' as http;
 
 import 'getHolidaysResponse.dart';
@@ -7,11 +6,10 @@ import 'getHolidaysResponse.dart';
 class GetHolidays {
   Future<GetHolidaysResponse> query() async {
     var response = (await http.get(Uri.parse('https://ferien-api.de/api/v1/holidays/HE'))).body;
+    var data = jsonDecode(response) as List<dynamic>;
     return GetHolidaysResponse(
         List<GetHolidaysResponseObject>.from(
-            jsonDecode(response).map<GetHolidaysResponseObject>(
-                    GetHolidaysResponseObject.fromJson
-            )
+            data.map<GetHolidaysResponseObject>((e) => GetHolidaysResponseObject.fromJson(e as Map<String, dynamic>))
         )
     );
   }