When reading below document via OpenApiStringReader, it no longer throws OpenApiUnsupportedSpecVersionException exception with v1.1.0-preview.4, it used to be thrown with v1.0.0 is there a reason why this behavior was changed.

{
"swagger": "1.0",
"info": {
"title": "This is a simple example",
"version": "1.0.0"
},
"host": "example.org",
"basePath": "/api",
"schemes": [
"http",
"https"
],
"paths": {}
}