spec: clean up spec pollution in speed_graderSpec.js
spec: clean up spec pollution in speed_graderSpec.js

Test Plan:
1. specs pass

Change-Id: I128258ee454447fc23183a6898a47752d21776d4
Reviewed-on: https://gerrit.instructure.com/123868
Tested-by: Jenkins
Reviewed-by: Shahbaz Javeed <6692d7be3fa215e5483a121d6fb314def6049877@instructure.com>
Product-Review: Spencer Olson <7cc0890d6f1f70810a023e7173eca5724d6c8e49@instructure.com>
QA-Review: Spencer Olson <7cc0890d6f1f70810a023e7173eca5724d6c8e49@instructure.com>

venturehive/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms