Merge pull request #1352 from mozilla/greenkeeper-react-helmet-3.2.2

Update react-helmet to version 3.2.2 🚀

package.json

@@ -176,7 +176,7 @@
     "react-addons-css-transition-group": "15.3.2",
     "react-cookie": "0.4.8",
     "react-dom": "15.3.2",
-    "react-helmet": "3.1.0",
+    "react-helmet": "3.2.2",
     "react-onclickoutside": "5.7.1",
     "react-redux": "4.4.5",
     "react-router": "2.8.1",