SSL cert/key placeholders in main compose file
SSL cert/key placeholders in main compose file

Issues: MEN-891

Signed-off-by: mchalczynski <3a897b56ed6fc284ae11e3e7ec3ea48d098a7178@rndity.com>

GregorioDiStefano/integration,pasinskim/integration,pasinskim/integration,pasinskim/integration,GregorioDiStefano/integration