Flatten back the structure (#837)

* Remove chains.

* Move relay clients.

* Flatten generic.

* Fix fmt.

bridges/relays/messages/src/lib.rs

@@ -0,0 +1,36 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common 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.
+
+// Parity Bridges Common 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 Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Relaying [`pallet-bridge-messages`](../pallet_bridge_messages/index.html) application specific
+//! data. Message lane allows sending arbitrary messages between bridged chains. This
+//! module provides entrypoint that starts reading messages from given message lane
+//! of source chain and submits proof-of-message-at-source-chain transactions to the
+//! target chain. Additionaly, proofs-of-messages-delivery are sent back from the
+//! target chain to the source chain.
+
+// required for futures::select!
+#![recursion_limit = "1024"]
+#![warn(missing_docs)]
+
+mod metrics;
+
+pub mod message_lane;
+pub mod message_lane_loop;
+
+mod message_race_delivery;
+mod message_race_loop;
+mod message_race_receiving;
+mod message_race_strategy;