RPC & Client (#21)

* Initial version of http server.

* Refactor the structure.

* add unassigned ports info.

* Rename servers to match conventions.

* Add client crate and some proper RPC implementations.

* Style & docs.

substrate/rpc/src/chain/tests.rs

@@ -0,0 +1,39 @@
+// Copyright 2017 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot 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.
+
+// Polkadot 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 Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+use super::*;
+
+use test_helpers::Blockchain;
+
+#[test]
+fn should_return_header() {
+	let state = Blockchain::default();
+
+	assert_matches!(
+		ChainApi::header(&state, 0.into()),
+		Ok(Some(ref x)) if x == &block::Header {
+			parent_hash: 0.into(),
+			state_root: 0.into(),
+			timestamp: 0,
+			number: 0,
+		}
+	);
+
+	assert_matches!(
+		ChainApi::header(&state, 5.into()),
+		Ok(None)
+	);
+}