Bumps [async-std](https://github.com/async-rs/async-std) from 1.5.0 to 1.6.0.
- [Release notes](https://github.com/async-rs/async-std/releases)
- [Changelog](https://github.com/async-rs/async-std/blob/master/CHANGELOG.md)
- [Commits](https://github.com/async-rs/async-std/compare/v1.5.0...v1.6.0

)

Signed-off-by: dependabot-preview[bot] <[email protected]>

* Add descriptions for folder structure + node

* Beef up descriptions of project components

* Fix list formatting

* Add note about nightly Rust

* Update README.md

Co-authored-by: Tomasz Drwięga <[email protected]>

* Update README.md

Co-authored-by: Tomasz Drwięga <[email protected]>

* Reword Tomek's currency-exchange suggestion

* Add link to Substrate's installation guide

Co-authored-by: Tomasz Drwięga <[email protected]>

* ethereum exchange module

* continue

* continue

* added tests for exchange module

* moved

* remove println

* move again

* fixes

* removed redundant deps

* cargo fmt

* fund_locks_transaction_decode_works

* cargo fmt --all

* fix error processing

* added some tracing to bridge modules

* more tests

* more tests

* cargo fmt --all

* kovan.rs -> exchange.rs

* Update bin/node/runtime/src/exchange.rs

Co-authored-by: Tomasz Drwięga <[email protected]>

* added assumption doc

* Airdrop -> DepositInto

* AsIs -> Identity

* OnTransactionSubmitted

* Transfers::Key = Id

* typo

* Update bin/node/runtime/src/exchange.rs

Co-authored-by: Tomasz Drwięga <[email protected]>

* block+tx+proof -> proof { block, tx, proof }

* cargo fmt --all

* docs

* check <-> verify

* parse hex

* extracted exchange primitives to separate crate

* added docs to runtime::exchange module

* Update bin/node/runtime/src/exchange.rs

Co-authored-by: Hernando Castano <[email protected]>

* typo

* Update modules/currency-exchange/Cargo.toml

Co-authored-by: Hernando Castano <[email protected]>

* add docs to currency-exchange module

* change tests names

* cargo fmt --all

* Update bin/node/runtime/src/exchange.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update bin/node/runtime/src/exchange.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update bin/node/runtime/src/exchange.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update bin/node/runtime/src/exchange.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update bin/node/runtime/src/exchange.rs

Co-authored-by: Hernando Castano <[email protected]>

* fixed verify_transaction_finalized for siblings of finalized blocks

* cargo fmt --all

* added double spend note

* cargo fmt --all

Co-authored-by: Tomasz Drwięga <[email protected]>
Co-authored-by: Hernando Castano <[email protected]>

* bump substrate

* cargo fmt --all

* removeInMemoryStorage + extract Kovan stuff to runtime

* removed comment from the future

* limit number of headers that are pruned within single import Call

* verify that pruning range upper bottom is always-increasing

* Fix typo

Co-authored-by: Hernando Castano <[email protected]>

* removeInMemoryStorage + extract Kovan stuff to runtime

* removed comment from the future

* remove redundant conversions

* remove redundant `u8 as usize`

* remove redundant `u8 as usize`

* Update modules/ethereum/src/mock.rs

Co-authored-by: Hernando Castano <[email protected]>

* use hex-literal in kovan config

* cargo fmt --all

* extracted insert_header

* cargo fmt --all

Co-authored-by: Hernando Castano <[email protected]>

The runtime requires nightly to build, but there's an issue with the
nightly releases from 2020-05-25 and onwards which is causing builds
to fail. This rolls back the version of the nightly compiler so that
builds pass until a fix is found.

* Test defining an RPC API

* Add wrapper clients for the RPC API

* Implement most Ethereum RPCs

Does not include RPCs that require the bridge contract.

* Implement a few of the Substrate RPCs

Still missing proper error handling, as well as decoding responses from the
Substrate node.

* Make error handling more ergonomic

* Implement Substrate RPCs that use `state_call`

* Implement rest of Substrate RPCs

* Implement `eth_call` RPC

This can be used to implement higher level requests like fetching Substrate headers
from an Ethereum node.

* Build some of the higher level Ethereum RPCs

Uses the new Ethereum RPC interface to do so

* Build some of the higher level Substrate RPCs

* Remove old Ethereum RPC methods

* Remove old Substrate RPC methods

* Add some documentation to Substrate RPCs

* Fix typo in enum construction

* Revert commits `0f0435d2` to `ca755029`

This range of commits was mainly trying to integrate the new RPC interface into the existing
codebase, however this turned out to be a little out of scope for the current PR. Instead this work
will be incorporated into a PR which aims to close #72.

* Add documentation to RPCs

* Rename functions in RPC API to conform to snake_case

* Check that header contains a number and hash

* Put doc comments on trait instead of impl methods

* Remove expect() calls

* Replace runtime API enums with consts

* Accept Bytes when submitting extrinsic

Let's us avoid using a runtime specific Extrinsic.

* Add strictly typed arguments to RPC API

Missing two methods right now, which require a `serde::Deserialize`
implemenation before they can be changed.

* Add `chain_getBlock` Substrate RPC

* Use typed arguments for `eth_estimateGas` and `eth_call`

* Silence dead code warnings

* Add check for logs bloom

* Remove unused variables

* Add documentation to RPC error enums

* Use `CallRequest` type from rust-web3 crate

* Change CallRequest's `to` field to be optional

Required due to changes in upstream `rust-web3` crate.

* mute warnings from sub2sub module+relay

* cargo fmt --all

* Bump rust-web3 to latest master

* Use tagged release from crates.io

* Add check for `logs_bloom`

Since this is required by the runtime we want to enforce that an
incoming header has this.

* solidity contract

* continue

* upd

* cargo update

* fixes

* ehtereum_headers -> headers

* extracted some common stuff

* ethereum_sync.rs -> sync.rs

* make sync generic

* continue extracting

* continue

* add eth-contract argument

* continue

* some fixes

* contract v2

* continue

* more fixes

* more fixes

* deal with duplicated params

* removed multiple call_rpc variants

* bail_on_error!()

* fn submit_ethereum_transaction

* more fixes

* cargo fmt --all

* fix

* bail_on_arg_error!()

* fix

* fix

* remove async_extra stuff

* start work on finality builtin

remove async_extra stuff

continue

continue

local testnet (Alice + Bob) for node

* added TODO

* substrate-bridge.json -> substrate-bridge-abi.json

* get rid of substrate transactions hashes

* get rid of ethereum transactions hashes

* extracted contract bytecode to separate file

* cargo fmt --all

* avoid duplicate import in contracts

* removed Default::default()

* swapped configurations for sub2eth && eth2sub

* fix compilation

* do not double gas limit when submitting Substrate headers

* fix finality storage

* at least 1 validator required

* shift_session_manager_works

* cargo fmt --all

* solidity contract removed

* consts

* extracted solc compilation details to separate file

* removed (obsolete in future Vec<u8> justification)

* fixed cli option description

* fix typos

* fix grumble

* extracted constants

* log decoded header

* new substrate version + actually verify justification

* intermediate cargo fmt --all

* comments

* disable completion data resubmission

* increased timeouts + _MS -> Duration

* forget completion data after submission

* builtin tests

* headers tests

* cargo fmt --all

* update contract

* Update relays/ethereum/src/ethereum_sync_loop.rs

Co-authored-by: Tomasz Drwięga <[email protected]>

* Update relays/ethereum/src/ethereum_sync_loop.rs

Co-authored-by: Tomasz Drwięga <[email protected]>

* added docs

* OwnedFutureOutput

* more docs fixes

* cargo fmt --all

* encode headers

* consts + docs

* aliases again

* cargo fmt --all

* Update relays/ethereum/src/ethereum_sync_loop.rs

Co-authored-by: Tomasz Drwięga <[email protected]>

* Update relays/ethereum/src/ethereum_sync_loop.rs

Co-authored-by: Tomasz Drwięga <[email protected]>

* Use Duration::from_secs() instead of from_millis()

* grumbles

* Update relays/ethereum/src/headers.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update relays/ethereum/src/headers.rs

Co-authored-by: Hernando Castano <[email protected]>

* incomplete_headers_are_still_incomplete_after_advance

* add hex-encoded headers to substrate_header_without_signal_parsed

* cargo fmt --all

* Update relays/ethereum/src/sync_loop.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update relays/ethereum/src/headers.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update relays/ethereum/src/headers.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update relays/ethereum/src/headers.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update relays/ethereum/src/headers.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update relays/ethereum/src/headers.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update relays/ethereum/src/headers.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update relays/ethereum/src/headers.rs

Co-authored-by: Hernando Castano <[email protected]>

* added comments on Extra and Completion

Co-authored-by: Tomasz Drwięga <[email protected]>
Co-authored-by: Hernando Castano <[email protected]>

* solidity contract

* continue

* upd

* cargo update

* fixes

* ehtereum_headers -> headers

* extracted some common stuff

* ethereum_sync.rs -> sync.rs

* make sync generic

* continue extracting

* continue

* add eth-contract argument

* continue

* some fixes

* contract v2

* continue

* more fixes

* more fixes

* deal with duplicated params

* removed multiple call_rpc variants

* bail_on_error!()

* fn submit_ethereum_transaction

* more fixes

* cargo fmt --all

* fix

* bail_on_arg_error!()

* fix

* fix

* remove async_extra stuff

* substrate-bridge.json -> substrate-bridge-abi.json

* get rid of substrate transactions hashes

* get rid of ethereum transactions hashes

* extracted contract bytecode to separate file

* cargo fmt --all

* avoid duplicate import in contracts

* removed Default::default()

* swapped configurations for sub2eth && eth2sub

* fix compilation

* do not double gas limit when submitting Substrate headers

* cargo fmt --all

* solidity contract removed

* consts

* extracted solc compilation details to separate file

* removed (obsolete in future Vec<u8> justification)

* fixed cli option description

* fix typos

* fix grumble

* extracted constants

* log decoded header

* cargo fmt --all

* comment

* new substrate version + actually verify justification

* cargo update + fix remaining stuff

* add weight=0 comments

* cargo fmt --all

* fix hash types