An option to create security groups and roles from existing yaml config

[PetrGlad]

Use case: I want to create production version of test stack for which I already have configuration file.
I want to copy the configuration, adjust parameters to be suitable for production environment (mostly configuration stays the same) and then create stack for it. So I want to init new app without generating config, using existing one.
Currently I can work around by launching "senza init deleteme.yaml" to let it create security groups and then discard deleteme.yaml which is rather inconvenient and error prone.

[ender74]

would be great to have this feature