fix unreliable question creation selenium specs

Change-Id: I93c40f81ca0fd154f608a28c4b2a71631fee734a
Reviewed-on: https://gerrit.instructure.com/29477
Reviewed-by: Bryan Madsen <bryan@instructure.com>
Product-Review: Bryan Madsen <bryan@instructure.com>
QA-Review: Bryan Madsen <bryan@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>