spec: fix migration "spec"

Change-Id: I2d3b36cfdccb2d133ff927348ad6e0e1f9468e5b
Reviewed-on: https://gerrit.instructure.com/29884
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Bracken Mosbacker <bracken@instructure.com>
Product-Review: Bracken Mosbacker <bracken@instructure.com>
QA-Review: Bracken Mosbacker <bracken@instructure.com>