* fix(signers): make Signer send by blocking on Ledger calls
* fix(providers): use Arc in WS impl to allow cloning
* feat(middleware): add geometric gas price escalator
* test(middleware): ensure that we can still stack everything up
* fix(middleware): default to tokio/async-std
* chore: fix clippy
* docs(middleware): add docs and rename middlewares
* chore: fix doctests
* feat: add linear gas escalator
https://github.com/makerdao/pymaker/blob/master/tests/test_gas.py\#L107https://github.com/makerdao/pymaker/blob/master/pymaker/gas.py\#L129
* feat: add constructors to gas escalators
* feat: ledger support
Adds support for Ledger Nano S Eth app (v1.3.7)
- sign message
- sign transaction
- get addresses
- get app version
* fix: fix eth docstring
* fix: take into account EIP155
* feat: convert Signer to async
* feat: implement Signer for Ledger
* ci: run celo-only tests explicitly
This is done to avoid using --all-features
* fix: remove async from with_signer
* chore: fix doctests
* fix: add Send/Sync to SignerError
* ci: update etherscan key
* test: disable etherscan abigen tests temporarily