(maint) Update smoke-test ticket description

Now that we are testing service scripts and passenger in Puppet
acceptance with package installs, we no longer need to smoke test deb
and rpm packages. I've updated the description of the smoke-test ticket
to reflect this.
Now might be a good time to add cent7 to the list, or to fold it into the rhel line.
` RHEL/CentOS 5/6/7`