init base for swagger-ui canvas-api docs

fixes SIS-181
fixes SIS-188

Change-Id: I7375376e832abbbea1240323874c624eb8dd40e0
Reviewed-on: https://gerrit.instructure.com/30668
QA-Review: Jeremy Putnam <jeremyp@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Eric Adams <eadams@instructure.com>
Reviewed-by: Duane Johnson <duane@instructure.com>