avoid temp tables in sis batch batch mode

we don't want them in a transaction, and they don't work
through pgbouncer without a transaction

Change-Id: Ia1845085db6cda1d039a91588fff2cb4fd93012f
Reviewed-on: https://gerrit.instructure.com/37554
Reviewed-by: Jacob Fugal <jacob@instructure.com>
Reviewed-by: Rob Orton <rob@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>