Add support for Elasticsearch version 7.5.*

Upgrade elasticsearch-rest-client to 7.5.0. Upgrade httpcore-nio to
4.4.12 as a consequence.

Add V7_5 to the version manager, and use this in all the V7 tests.

Use the 7.5.0 image from blacktop in the test container.

Change-Id: I9e3e9b586e8e7c2b788f1f2240a175600b7b0b47
9 files changed
tree: b9c6dc81e5c29bc9851637d05f1003a8e71893b8
  1. java/
  2. javatests/