* fix: dual license MIT / Apache 2 * provider: add missing license
* 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
* feat(signers): implement Serde and make API smaller * fix: add abigen as a dev-dependency feature