Update what's new

dist/preview release/what's new.md

@@ -134,6 +134,7 @@
 - Added support for 8 bone influences to glTF loader ([zeux](https://github.com/zeux))
 - Added support for animations import from separate files ([noalak](https://github.com/noalak/))
 - Use web workers to validate glTF to avoid blocking the main thread. ([bghgary](https://github.com/bghgary))
+- Update glTF validator to 2.0.0-dev.3.1. ([bghgary](https://github.com/bghgary))
 
 ### Materials