This validation will run only on RedHat OS family (CentOS, Fedora, ...).
It calls the "rpm --verify|-V" command on the selected package, and
return its status.
Some notes:
- if the package isn't installed, it will fail
- if the package is present, but doesn't have the %verifyscript
scriptlet, it won't fail
- "become" is needed, especially if the verification script in the RPM
calls some root-only things, such as "semodule" (this is the case for
openstack-selinux, for instance)
- if you set the validation to verbose, most of the output will be in
the stdout - you therefore will have to go through the validation log
to get the complete reason
Change-Id: I7be310cac60b6729aa3c1a67f731421f85a78d80
566dc28121