Fix uplink setup step for uplink versions that requires an access field.
Update how script selects uplink versions to test.
Use significantly smaller remote files for test (performance).
Change-Id: If590b8798767e2a0621fb84cd3b8852d02f6d1da
stage
The test-versions script no longer uses the `testfiles` directory, which
the final upload for the rolling-upgrade script depended on. This change
creates and populates a `testfiles` diirectory during the final upload
stage of the rolling upgrade test.
Change-Id: Iabeccbadc55a8c85a1febbd5eb4e7d889a57a8dc
