Add react and react-dom as peer dependencies

Fixes errors using Yarn 2 (berry).

See ant-design/ant-design#27339 for details.

Author: brandonbloom

package.json

@@ -59,5 +59,9 @@
   },
   "maintainers": [
     "[email protected]"
-  ]
+  ],
+  "peerDependencies": {
+    "react": "^16.10.2",
+    "react-dom": "^16.10.2"
+  }
 }