Add coucou to ssh ansible

Signed-off-by: Arnaud M. <arnaud.choupinette@mailops.fr>

ansible/training/lessons/2-inventory.md

@@ -33,7 +33,7 @@ Finally, we tell ansible to use `python3` interpreter (default is `python`, but
 ### Check if running
 Try to connect on your demo machine, to see if it's running:
 ```
-ssh -p 2222 root@127.0.0.2
+ssh -p 2222 root@127.0.0.2 'echo "coucou from $(hostname)"'
 ```
 
 ### ping