BooleanValidator validates any data as true for type: "boolean" #271

Description

Found while testing oneOf support (#201 / PR #267). BooleanValidator effectively validates any data as true for schemas declaring type: "boolean" — non-boolean data is accepted instead of failing validation.

Reproduction

{ "type": "boolean" }

validated against 42 (or "hello", or any non-boolean) returns valid.

Expected

Only actual booleans (true/false) should validate against type: "boolean"; anything else should produce a validation error.