subscription_holder 2.0.0+2

Subscription Holder holds StreamSubscriptions and dispose all conveniently.

2.0.0

• Change SubscriptionHolderMixin to on StateNotifier from with Disposabe
  • Previously, dispose can override the dispose of base class, so eliminate that situation by limiting usage.

1.2.0+1

• Depends on subscription_holder

1.1.0

• Upgrade dependencies

1.0.0

• Initial release.