Merge pull request #2549 from LLK/greenkeeper/react-modal-3.5.1

Update react-modal to the latest version 

package.json

@@ -82,7 +82,7 @@
     "react-draggable": "3.0.5",
     "react-ga": "2.5.3",
     "react-intl": "2.4.0",
-    "react-modal": "3.4.4",
+    "react-modal": "3.5.1",
     "react-popover": "0.5.7",
     "react-redux": "5.0.7",
     "react-responsive": "5.0.0",