remove membership metadata

closes #129 (closed) (removes the code responsible of the error)

And add fixme_tests.rs file to show behavior that are bugs

pallets/authority-members/src/benchmarking.rs

@@ -59,7 +59,7 @@ benchmarks! {
         let caller: T::AccountId = Members::<T>::get(id).unwrap().owner_key;
         let caller_origin: <T as frame_system::Config>::RuntimeOrigin = RawOrigin::Signed(caller.clone()).into();
             let validator_id = T::ValidatorIdOf::convert(caller.clone()).unwrap();
-            let session_keys: T::KeysWrapper = pallet_session::NextKeys::<T>::get(validator_id).unwrap().into();
+            let session_keys: T::Keys = pallet_session::NextKeys::<T>::get(validator_id).unwrap().into();
         }: _<T::RuntimeOrigin>(caller_origin, session_keys)
      remove_member {
         let id: T::MemberId = OnlineAuthorities::<T>::get()[0];