Merge branch 'master' of github.com:builderbook/builderbook

Author: tima101

server/app.js

@@ -28,6 +28,7 @@ const options = {
   useNewUrlParser: true,
   useCreateIndex: true,
   useFindAndModify: false,
+  useUnifiedTopology: true,
 };
 
 mongoose.connect(MONGO_URL, options);