fix user_spec favorites specs for rails 3

Change-Id: I7e783504c6134099014254f1fffd68366ab488d1
Reviewed-on: https://gerrit.instructure.com/29717
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>
Product-Review: James Williams  <jamesw@instructure.com>
QA-Review: James Williams  <jamesw@instructure.com>