fix wiki page spec for rails 3

Change-Id: If89faa2ad16eb7846975528cda98cb24bd3f4902
Reviewed-on: https://gerrit.instructure.com/29693
Reviewed-by: Jon Willesen <jonw@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>