spec: selenium 2.39 upgrade

Change-Id: I64f3b568cff9a6cdaa0beb689c5a44f90447f1f1
Reviewed-on: https://gerrit.instructure.com/28374
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Bryan Madsen <bryan@instructure.com>
Product-Review: Bryan Madsen <bryan@instructure.com>
QA-Review: Bryan Madsen <bryan@instructure.com>