use latest version in example

dbu · web-flow · commit 0db429e97725 · 2018-09-11T15:09:05.000+02:00
diff --git a/setup/flex.rst b/setup/flex.rst
@@ -111,7 +111,7 @@ Symfony application by executing the following command:
 
 .. code-block:: terminal
 
-    $ composer create-project symfony/skeleton:3.4.* my-project
+    $ composer create-project symfony/skeleton:4.1.* my-project
 
 .. note::
 
