indexBy was renamed to keyBy in lodash 4

Author: tiennou

lib/backend/api/index.js

@@ -39,7 +39,7 @@ module.exports = function (config) {
         return db.users.find({ _id: { $in: _.map(messages, '_id') } })
           .then(users => {
             users = users.map(i => _.pick(i, ['_id', 'username', 'badge']))
-            return { messages, users: _.indexBy(users, '_id') }
+            return { messages, users: _.keyBy(users, '_id') }
           })
       })
   }))