----------------
High-level changes:
- Dropped ``aiohttp`` library in favor of using ``asks``.
- This adds support for asyncio, trio, and curio async loops.
- Dropped synchronous interface on FieldClimateClient.
**This means all client methods must now be awaited.**
Implementation changes:
- Moved url validation functions from ``fieldclimate.utils`` to ``fieldclimate.clean``.
These functions now raise ``AssertionError`` explicitly, as ``assert`` statements can be switched off.
- FieldClimateClient now inherits from ``asks.Session``,
which provides async context manager usage and connection rate limiting.
- Removed BaseClient and HmacClient classes, unifying their functionality in FieldClimateClient.
- Added tests for trio and curio event loops.
Bonus changes:
- Added DjangoFieldClimateClient.
This subclass gets your HMAC authentication keys from django's settings,
which can save you a few lines of code if you already use django.