generate address book jwts with HS512 algorithm
generate address book jwts with HS512 algorithm

closes RECNVS-388
refs RECNVS-387

test plan:
* smoke test that address book still works with canvas

Change-Id: I01fb1802f748494ac056eab26b196a7a4f7de10e
Reviewed-on: https://gerrit.instructure.com/150614
Reviewed-by: Jacob Fugal <f862f167b85d41b225785c70d70808bc7337c1fe@instructure.com>
Tested-by: Jenkins
QA-Review: Collin Parrish <aa381382ccdcc876f5cf7879d921ed03200f6804@instructure.com>
Product-Review: Xander Moffatt <27f70fe194da423604e6e0a63a3de19814736fa9@instructure.com>

instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,djbender/canvas-lms