spec: fix fragile grading period tests
spec: fix fragile grading period tests

Change-Id: I78c0a66969d9128b40a03a88d47de8dc11047614
Reviewed-on: https://gerrit.instructure.com/99422
Tested-by: Jenkins
Reviewed-by: Jeremy Neander <20252aad5efdc666f083d82ab63ed0f9f72a043e@instructure.com>
Reviewed-by: Shahbaz Javeed <6692d7be3fa215e5483a121d6fb314def6049877@instructure.com>
Product-Review: Spencer Olson <7cc0890d6f1f70810a023e7173eca5724d6c8e49@instructure.com>
QA-Review: Spencer Olson <7cc0890d6f1f70810a023e7173eca5724d6c8e49@instructure.com>

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