Merge pull request brianegan#177 from mono0926/fix-value_notifier_provider-memory-leak

Fix ValueNotifierProvider memory leak

Author: brianegan

freezed_provider_value_notifier/lib/value_notifier_provider.dart

@@ -17,6 +17,7 @@ class ValueNotifierProvider<Controller extends ValueNotifier<Value>, Value>
   Widget buildWithChild(BuildContext context, Widget child) {
     return InheritedProvider(
       create: create,
+      dispose: (context, Controller controller) => controller.dispose(),
       child: DeferredInheritedProvider<Controller, Value>(
         create: (context) => context.read<Controller>(),
         startListening: (context, setState, controller, _) {