Add kusama runtime and example (#75)

examples/kusama_balance_transfer.rs

@@ -0,0 +1,47 @@
+// Copyright 2020 Parity Technologies (UK) Ltd.
+// This file is part of substrate-subxt.
+//
+// subxt is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// subxt is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with substrate-subxt.  If not, see <http://www.gnu.org/licenses/>.
+
+use sp_keyring::AccountKeyring;
+use substrate_subxt::{
+    balances,
+    Error,
+    system::System,
+    KusamaRuntime,
+};
+
+fn main() {
+    async_std::task::block_on(async move {
+        env_logger::init();
+
+        let xt_result = transfer_balance().await;
+        match xt_result {
+            Ok(hash) => println!("Balance transfer extrinsic submitted: {}", hash),
+            Err(_) => eprintln!("Balance transfer extrinisic failed"),
+        }
+    });
+}
+
+async fn transfer_balance() -> Result<sp_core::H256, Error> {
+    let signer = AccountKeyring::Alice.pair();
+    let dest = AccountKeyring::Bob.to_account_id();
+
+    // note use of `KusamaRuntime`
+    substrate_subxt::ClientBuilder::<KusamaRuntime>::new()
+        .build().await?
+        .xt(signer, None).await?
+        .submit(balances::transfer::<KusamaRuntime>(dest.clone().into(), 10_000))
+        .await
+}