fix fragility of ember quiz index integration specs

Change-Id: I1eabc12c422f7c028ff92d21726aa14083d27c09
Reviewed-on: https://gerrit.instructure.com/31772
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Jason Madsen <jmadsen@instructure.com>
Product-Review: Stanley Stuart <stanley@instructure.com>
QA-Review: Stanley Stuart <stanley@instructure.com>