Expunge error-chain (feat. tomaka) (#2662)

* Remove error_chain

* Expunge error-chain from rpc and service.

* Expunge from transaction pool.

* Expunge from node/cli

* Expunge from keystore.

* Remove some boilerplate.

* Fix remaining stuff.

* Improve on deprecation message.

* Fix issues.

* Fix trnsaction pool tests.

* Fix the rest.

* Fix borked merge.

* Update lock

substrate/node/cli/src/error.rs

@@ -1,32 +0,0 @@
-// Copyright 2018-2019 Parity Technologies (UK) Ltd.
-// This file is part of Substrate.
-
-// Substrate 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.
-
-// Substrate 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.  If not, see <http://www.gnu.org/licenses/>.
-
-//! Initialization errors.
-
-use client;
-use error_chain::{
-	error_chain, error_chain_processing, impl_error_chain_processed
-};
-
-error_chain! {
-	foreign_links {
-		Io(::std::io::Error) #[doc="IO error"];
-		Cli(::clap::Error) #[doc="CLI error"];
-	}
-	links {
-		Client(client::error::Error, client::error::ErrorKind) #[doc="Client error"];
-	}
-}

substrate/node/cli/src/service.rs

@@ -31,7 +31,7 @@ use node_runtime::{GenesisConfig, RuntimeApi};
 use substrate_service::{
 	FactoryFullConfiguration, LightComponents, FullComponents, FullBackend,
 	FullClient, LightClient, LightBackend, FullExecutor, LightExecutor, TaskExecutor,
-	error::{Error as ServiceError, ErrorKind as ServiceErrorKind},
+	error::{Error as ServiceError},
 };
 use transaction_pool::{self, txpool::{Pool as TransactionPool}};
 use inherents::InherentDataProviders;
@@ -92,7 +92,7 @@ construct_service_factory! {
 
 					let client = service.client();
 					let select_chain = service.select_chain()
-						.ok_or_else(|| ServiceError::from(ServiceErrorKind::SelectChainRequired))?;
+						.ok_or(ServiceError::SelectChainRequired)?;
 					executor.spawn(start_aura(
 						SlotDuration::get_or_compute(&*client)?,
 						key.clone(),