Fix version mismatch

playground/package.json

@@ -11,8 +11,8 @@
   },
   "dependencies": {
     "@microsoft/tsdoc": "0.12.13",
-    "@types/react": "16.9.1",
-    "@types/react-dom": "16.8.5",
+    "@types/react": "16.9.2",
+    "@types/react-dom": "16.9.0",
     "promise": "~8.0.3",
     "monaco-editor": "~0.17.1",
     "tslib": "~1.10.0"