update dynamo-local-admin appliance
update dynamo-local-admin appliance

- Upgrade from openjdk/8-jre to openjdk/11-jre-slim
- Cut image size from 613MB to 471MB
- Upgrade to Node.js 10.x (from 8.x)
- Upgrade dynamo-admin from 2.0.2 to 3.1.1

Change-Id: I989592162f01b1c4399d73d6c81e6e8206080284
Reviewed-on: https://gerrit.instructure.com/181135
Tested-by: Jenkins
Reviewed-by: Ryan Taylor <2eafa1f6bf34395b543d6ca7f438461b0774d24f@instructure.com>
QA-Review: Bryan Petty <33564f6eff3d808d3eaaa056a1631fdcde5faed6@instructure.com>

instructure/dockerfiles,instructure/dockerfiles,instructure/dockerfiles,instructure/dockerfiles