The script looks to be completing without error in my testing as well as
in the original issue so I am forcing an exit with 0 until the cause can
be found.
Fixes#23
1. Now does not remove prerequisite packages, lvm2 was included in
these packages (not good when you use LVM2 for real).
2. Added a bit more idempotency to the shell scripts - only delete if
it exists.
3. Check that the process isn't running and binaries are gone.