Drop asynchronous property
- [x] Update to DunitePy v1.0 which removes the asynchronous property, removes `aiohttp` and adds `websocket-client` dependencies
- In runtime and tests environments remove:
- [x] `async`/`await` keywords
- [x] `client.close()` which is now handled by DuniterPy after each request
- Clean other stuff
- [x] Remove `pytest-asyncio` and `asynctest` dev dependencies
issue