qi_stage_script: Implement.

Change-Id: Ia8ce769c94ec337580e7476dda0c6994080cd66e
Reviewed-on: http://gerrit.aldebaran.lan:8080/18425
Tested-by: gerrit
Reviewed-by: dmerejkowsky <dmerejkowsky@aldebaran-robotics.com>
Reviewed-by: mnottale <mnottale@aldebaran-robotics.com>
Tested-by: mnottale <mnottale@aldebaran-robotics.com>