GRANDPA finality proof draft (#1268)

* grandpa finality proof

* prove GrandpaApi::grandpa_authorities using parent block + some docs

* create justification when consensus data is changed

* generate justifications periodically

* test for ConsensusChanges

substrate/core/transaction-pool/graph/src/pool.rs

@@ -327,7 +327,7 @@ mod tests {
 		/// Verify extrinsic at given block.
 		fn validate_transaction(&self, at: &BlockId<Self::Block>, uxt: &ExtrinsicFor<Self>) -> Result<TransactionValidity, Self::Error> {
 			let block_number = self.block_id_to_number(at)?.unwrap();
-			let nonce = uxt.transfer.nonce;
+			let nonce = uxt.transfer().nonce;
 
 			if nonce < block_number {
 				Ok(TransactionValidity::Invalid)
@@ -359,15 +359,12 @@ mod tests {
 
 		/// Hash the extrinsic.
 		fn hash(&self, uxt: &ExtrinsicFor<Self>) -> Self::Hash {
-			(uxt.transfer.from.to_low_u64_be() << 5) + uxt.transfer.nonce
+			(uxt.transfer().from.to_low_u64_be() << 5) + uxt.transfer().nonce
 		}
 	}
 
 	fn uxt(transfer: Transfer) -> Extrinsic {
-		Extrinsic {
-			transfer,
-			signature: Default::default(),
-		}
+		Extrinsic::Transfer(transfer, Default::default())
 	}
 
 	fn pool() -> Pool<TestApi> {