add react-dom dependency

Author: clehner

package.json

@@ -20,7 +20,8 @@
   },
   "homepage": "https://github.com/patchkit/patchkit-vertical-filled#readme",
   "dependencies": {
-    "react": "^0.14.6"
+    "react": "^0.14.6",
+    "react-dom": "^0.14.8"
   },
   "devDependencies": {
     "babel": "^6.3.26",