Package server provides functionality so that other uses of sansshell can provide their
own main.go without having to cargo-cult everything across for common use cases.
i.e. adding additional modules that are locally defined.
Run takes the given context, logger and policy and starts up a sansshell server using the flags above
to provide credentials.
As this is intended to be called from main() it doesn't return errors and will instead exit on any errors.