* feat(types): add optional Celo support
* feat: add Celo feature flags to all crates
* test(provider): add get_transaction celo test
* test(signer): add send_transaction celo test
* test(contract): add deploy and call contract function celo test
* fix(provider): ensure the Pending transaction calls the waker to get polled again
* feat(core): allow setting the blocktime in ganache
* test(provider): move pending txs test to integration tests + use block time
* fix(signers): make EIP-155 optional and fix sighash generation bug