- update to 0.11.1:
- Support Python 3.6.
- Drop support for Python 2.6, 3.1 and 3.2.
- Allow to use nested schema and allow any validator to be compiled.
- Default values MUST now pass validation just as any regular value.
This is a backward incompatible change if a schema uses default values
that don't pass validation against the specified schema.
- Modify `__lt__` in Marker class to allow comparison with non Marker
objects, such as str and int.
- Add description field to `Marker` instances.
- Add `Schema.infer` method for basic schema inference.
- Add `SomeOf` validator.
- Treat Python 2 old-style classes like types when validating.
- Make `IsDir()`, `IsFile()` and `PathExists()` consistent between
different Python versions.
- Use absolute imports to avoid import conflicts.
- Fix `Coerce` validator to catch `decimal.InvalidOperation`.
- Make `Schema([])` usage consistent with `Schema({})`.
- Allow partial validation when using validate decorator.
- Make `Schema.__eq__` deterministic.
- Replace implementation of `Maybe(s)` with `Any(None, s)` to allow
it to be compiled.