README.md in atrium-ruby-0.4.2 vs README.md in atrium-ruby-0.4.3

- old
+ new
@@ -3,9 +3,10 @@
 A Ruby wrapper for use with the [MX Atrium API](https://atrium.mx.com). In order to make requests, you will need to [sign up for MX Atrium API](https://atrium.mx.com/developers/sign_up) and get a `MX-API-KEY` and `MX-CLIENT-ID`. Then, configure your instance with:
 ```ruby
 Atrium.configure do |config|
   config.mx_api_key = YOUR_API_KEY
   config.mx_client_id = YOUR_CLIENT_ID
+  config.base_url = "https://atrium.mx.com" # base_url is set to "https://vestibule.mx.com" by default
 end
 ```
 
 From there, you can start using some basic class methods to make calls for data. See our [full documentation](https://atrium.mx.com/documentation) for more details.
 