ValidatePatternProperties applied only to additionalProperties

[vdwanderley]

When we add a patternProperties validation to a json schema, calling schema.Validate() validates only additional properties.
I don't know if this behavior is intended, but I believe this unit test should have passed:

[Fact]
public void When_property_value_doesnt_match_pattern_then_validation_fails()
{
    //// Arrange
    var schema = new JsonSchema();
    schema.Type = JsonObjectType.Object;
    schema.Properties.Add("capitallettersonly", new JsonSchemaProperty() { Type = JsonObjectType.String });
    schema.AllowAdditionalProperties = false;
    schema.PatternProperties.Add("^[a-z]+$", new JsonSchemaProperty() { Pattern = "^[A-Z]+$" });

    var token = new JObject();
    token.Add("capitallettersonly", new JValue("lowercase"));

    //// Act
    var errors = schema.Validate(token);

    //// Assert
    Assert.Single(errors);
    Assert.Equal(ValidationErrorKind.PatternMismatch, errors.First().Kind);
}

If we look at JsonSchemaValidator.cs, we will notice that only additionalProperties are passed as argument.