Feature(mousetrap): Add mousetrap features to redux

common/app/utils/add-lang.js

@@ -0,0 +1,13 @@
+import supportedLanguages from '../../utils/supported-languages';
+
+const toLowerCase = String.prototype.toLowerCase;
+export function addLang(url, lang) {
+  const maybeLang = toLowerCase.call(url.split('/')[1]);
+  if (supportedLanguages[maybeLang]) {
+    return url;
+  }
+  if (supportedLanguages[lang]) {
+    return `/${lang}${url}`;
+  }
+  return `/en${url}`;
+}