- Multiple API changes to make working with lending easier
- Lending universe construction examples
- Add: `filter_for_base_tokens()`
- Add: `filter_for_chain()`
- Add: `DEXPair.get_base_token()` and `DEXPair.get_quote_token()`
- Add: `LendingReserveUniverse.can_leverage(token)`
- Add: `LendingReserveUniverse.limit_to_chain()`
- API update: Make all `Universe` members optional, as we can have lending only universes
- API update: `get_rates_by_reserve()` can take a lending reserve object as an argument
- API update: `Universe` checks constructor argument types are correct
- Deprecate: Useless methods on `Universe`