Rename `Ladder` class to `API`.
Remove urlsplit/unsplit in URL.__call__ and just append path.
Only copy URL params and not entire state. Remove deepcopy in favor of params.copy().
Rename uppercase_methods to upper_methods.
Update tests with changes to ladder.
Fix URL references for hammock and requests.
Add comparision section between hammock and ladder.
Fix syntax in examples.
Release v0.2.0.