Merge pull request reasonml#543 from bloodyowl/react-ref-fix

Fix currentDomRef type in ReactDOM

Author: rickyvetter

src/ReactDOMRe.re

@@ -114,7 +114,7 @@ type domRef;
 
 module Ref = {
   type t = domRef;
-  type currentDomRef = ref(Js.nullable(Dom.element));
+  type currentDomRef = React.ref(Js.nullable(Dom.element));
   type callbackDomRef = Js.nullable(Dom.element) => unit;
 
   external domRef: currentDomRef => domRef = "%identity";