re-order top of stack.sh

* do sanity checks earlier
* move logging up

Change-Id: I7d15bac199d6c4382d4a4d222784d34f2707da56
Merge branch 'cinder-backends' into dt-test
Merge branch 'add-pre-install' into dt-test
Merge branch 'new-ceph-backend' into dt-test
Merge branch 'reorder-stack.sh' into dt-test
Merge branch 'test-ini-improvements' into dt-test
Merge branch 'usb-prereq' into dt-test
Merge branch 'conf-tempest' into dt-test