* Add comprehensive tests for humanize.py module to improve coverage from 71% to 100%

- Add tests for _nested_getitem error handling (KeyError, IndexError, TypeError)
- Add tests for humanize_error with long error message truncation
- Add tests for validate_with_humanized_errors success and failure cases
- Add tests for edge cases with None data and multiple validation errors
- Improve overall test coverage from 89% to 90%

This addresses the missing coverage in humanize.py lines 19-22, 45, and 54-57.

* Fix import sorting with isort

* Feature: Support requiring anyOf a list of keys

This adds a new feature to Voluptuous, which is somewhat akin to what json-schema does with the special key `anyOf`.

`Schema({Required(Any('color', 'temperature', 'brightness')): str})` will validate that AT LEAST ONE of these three values is present. That doesn't preclude any individual validation on each of those fields to still apply.
That means that in the above example, if `color` is present, brightness doesn't need to be present. But if brightness is present, all other validations of brightness (like checking that its value is a number between 0 and 100) still apply.

* Simplify tests

* Format stuff like black wants it