Make APIs match

Python changes
* Nuke `from_action`
* Change `environment()` to `for_environment`
* Remove `environment` property
* Add tests for `raw_config` property

C# changes
* Rename `WithEnvironment()` to `ForEnvironment()`
* Nuke `Environment` property
* Change tests to match the python tests
* Fix bug that assumed there is always an `All` config entry
* Add tests for `RawConfig` property

Tasks
- [x] Make the set of tests for python and c# compatible, i.e. test for the same things.
- [x] Squash commits

This will fix #13.