Parser fails to have a error message when true is set for both readOnly,writeOnly property field

[r-sreesaran]

Parser fails to have a error message when true is set for both readOnly,writeOnly property field
https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#schemaObject

[r-sreesaran]

I will raise a PR with a failing test and then subsequently have the issue fixed.

[gracekarina]

closed by #1214 thanks @r-sreesaran