How was this docstring so incorrect :(
No more Context.clone
Start modifying config tests re: newer API
Update docstring/constructor signature
Update tests to remove use of kwargs
Update to remove mention of kwargs in-code
No more set_defaults/set_overrides
Fix up a still-failing test to be more accurate to expected API
Flesh out newer skiptests
Add defaults arg to load()
Rejigger in-__init__ hierarchy stuff & test that it 'broke'
Prepare for Env adapter
Dummy setup for _env_keys
Keys load now, need to lowercase for consistency
Implement base version of custom adapter.

Existing Env so small it's not worth working around.
Move Context creation into Executor, clean up Executor tests, etc