Aioeos

- Tested library against RPC node,
- EosAccount API,
- Support using EOS ABI objects as action payloads,
- Signing support in RPC client,
- Cached chain ID,
- Simplified Getting Started guide,
- EOSKey renamed to EosKey

- Improved docs and "Getting Started" guide,
- Added .coveragerc, fixed abstract class coverage,
- Added mypy,
- Fixed typechecking errors,
- Added docstrings,
- Added missing validation,
- Dropped custom String type,
- Cleaned up serializer.py,
- Bumped base58 to 2.0.0,
- Added tests for RPC client,
- Fixed typehints in docs,
- Added check for building docs

Initial release of aioeos.