[#556] Upgrade to openjdk 8u162.
[#556] Upgrade to openjdk 8u162.

The Docker images now use openjdk:8u162-jre-slim as the base image.

Fixes #556.

Signed-off-by: Kai Hudalla <6c3288b94355003a6c5f12ba233f9fc06ef02a62@bosch-si.com>
dejanb/hono,dejanb/hono,dejanb/hono