Ethtx

Changed
- Set field `W3CallTree.to_address` as optional [77](https://github.com/EthTx/ethtx/pull/77)

Fixed
- Fixed readme commas and delete unused mongo_database from example [80](https://github.com/EthTx/ethtx/pull/80)
- Parameters decoding fixes [81](https://github.com/EthTx/ethtx/pull/81)

Changed
- Return lowercase address if `ENS` provider can not resolve it to name [75](https://github.com/EthTx/ethtx/pull/75)

Changed
- Changed exception `Web3ConnectionException` to `NodeConnectionException`[68](https://github.com/EthTx/ethtx/pull/68)
- Changed `tests` directory structure [68](https://github.com/EthTx/ethtx/pull/68)
- All models now use `pydantic` [72](https://github.com/EthTx/ethtx/pull/72)
- Removed `jsonpickle` [72](https://github.com/EthTx/ethtx/pull/72)
- Changed the order of methods in `DecoderService` [72](https://github.com/EthTx/ethtx/pull/72)
- Update requirements (*requirements.txt* & *Pipfile*) [72](https://github.com/EthTx/ethtx/pull/72)
- Update **README** [72](https://github.com/EthTx/ethtx/pull/72)
- `strip()` every single node URL in `NodeConnectionPool` [72](https://github.com/EthTx/ethtx/pull/72)
- Refactored ENS provider, each time a new ens object is taken [71](https://github.com/EthTx/ethtx/pull/71)

Fixed
- Fixed types in models [72](https://github.com/EthTx/ethtx/pull/72)
- Fixed bug with empty args from `4byte` [72](https://github.com/EthTx/ethtx/pull/72)

Added
- Added node switcher - if one is unavailable, it uses the others available to connect with
node [68](https://github.com/EthTx/ethtx/pull/68)
- Extended function end event models [72](https://github.com/EthTx/ethtx/pull/72)
- Model tests added [72](https://github.com/EthTx/ethtx/pull/72)
- Catch more exceptions from `4byte.directory` (looks like the service is not always working
properly) [71](https://github.com/EthTx/ethtx/pull/71)
- Added more logging [71](https://github.com/EthTx/ethtx/pull/71)
- Added more exceptions [71](https://github.com/EthTx/ethtx/pull/71)

Fixed
- Fix tuple components processing [66](https://github.com/EthTx/ethtx/pull/66)

Fixed
- Fixed bug where mongo was using database called 'db', instead of one specified in connection
string [62](https://github.com/EthTx/ethtx/pull/62)

Changed
- Removed indexes -incompatibility with macOS [63](https://github.com/EthTx/ethtx/pull/63)

Fixed
- **ENS** name fix. The contract name was decoded incorrectly, because `None` (unresolved) address value was overwriting
the correct one [63](https://github.com/EthTx/ethtx/pull/63)