Adds a basic fpm pack

This PR adds a basic `fpm` pack. There are a few blockers from making this a full-fledged module (https://github.com/StackStorm/st2/issues/886 and https://github.com/StackStorm/st2/issues/887), but this will do the needful in a bare minimum for the CI/CD pipeline.
My dirty hack for now.

/cc @DoriftoShoes @manasdk @Kami