pin all the gems

Change-Id: I7f02aa4794f91aebc2fe3d02e249ef00ab3c80dd
Reviewed-on: https://gerrit.instructure.com/29784
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>