Description of problem:

The pre-upgrade script is not an integral part of the installation,
which can lead to being skipped, followed by running into another
issues related to this.

Steps to Reproduce:

1. refresh satellite repositories to the new version
2. run yum update -y, satellite-installer --upgrade

Actual results:

No pre-upgrade check is performed about sanity of the system

Expected results:

Pre-upgrade checks are run before proceeding with the upgrade. This
assumes https://bugzilla.redhat.com/show_bug.cgi?id=1184568 is
addressed, especially regarding rpm version locking, to minimize the
impact the initial yum update.