Load env file if it matches the current environment

Author: Christophe Graniczny

configuration.md

@@ -40,6 +40,8 @@ Your `.env` file should not be committed to your application's source control, s
 
 If you are developing with a team, you may wish to continue including a `.env.example` file with your application. By putting place-holder values in the example configuration file, other developers on your team can clearly see which environment variables are needed to run your application.
 
+If the value of the `APP_ENV` variable is set before bootstraping the app, Laravel will try to load a file that matches this environment and will fallback to the `.env` file. This variable can be set in a server configuration or in a command line tool. For example, the phpunit configuration file set `APP_ENV=testing`, Laravel will look for a `.env.testing` file first. If the file does not exist, the`.env` file will be used.
+
 <a name="determining-the-current-environment"></a>
 ### Determining The Current Environment