fix(package): update react-dnd-html5-backend to version 9.0.0

Closes #1128

Author: greenkeeper[bot]

package.json

@@ -58,7 +58,7 @@
     "query-string": "6.5.0",
     "react": "16.8.6",
     "react-dnd": "9.0.1",
-    "react-dnd-html5-backend": "8.0.3",
+    "react-dnd-html5-backend": "9.0.0",
     "react-dom": "16.8.6",
     "react-helmet": "5.2.1",
     "react-redux": "^5.1.1",