admin tools audit logging fragile specs

fixes: CNVS-12870

Adds timecop around the creation of the audit log records.  This will simulate
the data more accuratly and allow the sorting to be correct in the selenium
specs.

Test Plan: Automated tests should pass.

Change-Id: I160cf84570050b1dc713dac921dc44a2eeb40409
Reviewed-on: https://gerrit.instructure.com/34307
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>
QA-Review: August Thornton <august@instructure.com>
Product-Review: Nick Cloward <ncloward@instructure.com>