dependencies updated, breaking change in react-intl fixed

scripts/flatten-messages.js

@@ -25,8 +25,12 @@ let messages = globSync(MESSAGES_PATTERN)
   .map((file) => JSON.parse(file))
   .reduce((collection, descriptors) => {
     descriptors.forEach(({id, defaultMessage}) => {
+      if (!defaultMessage) {
+        return;
+      }
       if (collection.hasOwnProperty(id)) {
-          throw new Error(`Duplicate message id: ${id}`);
+        // Message is already defined.
+        throw new Error(`Duplicate message id: ${id}`);
       }
       collection[id] = defaultMessage;
     });