Update react-dnd to the latest version 🚀 (#1300)

* fix(package): update react-dnd to version 9.4.0

* fix(package): update react-dnd-html5-backend to version 9.4.0

* chore(package): update lockfile package-lock.json

Author: greenkeeper[bot]

package-lock.json

@@ -60,8 +60,8 @@
     "prop-types": "15.7.2",
     "query-string": "6.8.3",
     "react": "16.9.0",
-    "react-dnd": "9.3.4",
-    "react-dnd-html5-backend": "9.3.4",
+    "react-dnd": "9.4.0",
+    "react-dnd-html5-backend": "9.4.0",
     "react-dom": "16.9.0",
     "react-helmet": "5.2.1",
     "react-redux": "5.1.1",