Remove unused PoA<>Substrate bridge (#1210)

* Decouple the PoA bridge code from Rialto
* Remove Rialto PoA bridge code
* Remove relays/bin-ethereum code
* Remove relays/client-ethereum code
* Remove modules/ethereum code
* Remove modules/ethereum-contract-builtin code
* Remove PoA bridge documentation
* Remove primitives/ethereum-poa code
* Decouple Rialto from currency-exchange
* Fix building with runtime-benchmarks
* Fix should_encode_bridge_send_message_call test
    Because we removed some runtime modules/pallets, the
    substrate2substrate bridge pallet has a different index within
    the runtime so its calls have a different encoding.
    Update the test to use the new encoding.
* Update readme - no more PoA bridge
* Remove deployments/bridges/poa-rialto
    Also removes:
    - deployments/networks/eth-poa.yml
    - deployments/networks/OpenEthereum.Dockerfile
* Remove deployments/dev/poa-config
* Update deployments readme - no more PoA bridge
* Remove eth-related scripts
    Deletes:
    - deployments/networks/eth-poa.yml
    - scripts/run-openethereum-node.sh
* Remove poa-relay from gitlab-ci
* Dockerfiles to use substrate-relay as default
* Remove modules/currency-exchange code
* Remove primitives/currency-exchange code

Signed-off-by: acatangiu <adrian@parity.io>

bridges/bin/rialto/runtime/Cargo.toml

@@ -17,8 +17,6 @@ serde = { version = "1.0", optional = true, features = ["derive"] }
 
 # Bridge dependencies
 
-bp-currency-exchange = { path = "../../../primitives/currency-exchange", default-features = false }
-bp-eth-poa = { path = "../../../primitives/ethereum-poa", default-features = false }
 bp-header-chain = { path = "../../../primitives/header-chain", default-features = false }
 bp-message-dispatch = { path = "../../../primitives/message-dispatch", default-features = false }
 bp-messages = { path = "../../../primitives/messages", default-features = false }
@@ -26,9 +24,7 @@ bp-millau = { path = "../../../primitives/chain-millau", default-features = fals
 bp-rialto = { path = "../../../primitives/chain-rialto", default-features = false }
 bp-runtime = { path = "../../../primitives/runtime", default-features = false }
 bridge-runtime-common = { path = "../../runtime-common", default-features = false }
-pallet-bridge-currency-exchange = { path = "../../../modules/currency-exchange", default-features = false }
 pallet-bridge-dispatch = { path = "../../../modules/dispatch", default-features = false }
-pallet-bridge-eth-poa = { path = "../../../modules/ethereum", default-features = false }
 pallet-bridge-grandpa = { path = "../../../modules/grandpa", default-features = false }
 pallet-bridge-messages = { path = "../../../modules/messages", default-features = false }
 pallet-shift-session-manager = { path = "../../../modules/shift-session-manager", default-features = false }
@@ -80,8 +76,6 @@ substrate-wasm-builder = { git = "https://github.com/paritytech/substrate", bran
 [features]
 default = ["std"]
 std = [
-	"bp-currency-exchange/std",
-	"bp-eth-poa/std",
 	"bp-header-chain/std",
 	"bp-message-dispatch/std",
 	"bp-messages/std",
@@ -99,9 +93,7 @@ std = [
 	"pallet-authority-discovery/std",
 	"pallet-babe/std",
 	"pallet-balances/std",
-	"pallet-bridge-currency-exchange/std",
 	"pallet-bridge-dispatch/std",
-	"pallet-bridge-eth-poa/std",
 	"pallet-bridge-grandpa/std",
 	"pallet-bridge-messages/std",
 	"pallet-grandpa/std",
@@ -137,8 +129,6 @@ runtime-benchmarks = [
 	"frame-support/runtime-benchmarks",
 	"frame-system/runtime-benchmarks",
 	"libsecp256k1",
-	"pallet-bridge-currency-exchange/runtime-benchmarks",
-	"pallet-bridge-eth-poa/runtime-benchmarks",
 	"pallet-bridge-messages/runtime-benchmarks",
 	"sp-runtime/runtime-benchmarks",
 ]