Resolve "Upgrade substrate to august 2021 release"

Closes #9 (closed)

pallets/universal-dividend/src/lib.rs

@@ -175,7 +175,7 @@ pub mod pallet {
     // https://substrate.dev/docs/en/knowledgebase/runtime/events
     #[pallet::event]
     #[pallet::generate_deposit(pub(super) fn deposit_event)]
-    #[pallet::metadata(T::AccountId = "AccountId")]
+    #[pallet::metadata(T::AccountId = "AccountId", BalanceOf<T> = "Balance")]
     pub enum Event<T: Config> {
         /// A new universal dividend is created
         /// [ud_amout, members_count]