[Integrated] RFR: Switch to GitHub's new review comment positioning API

[Robin Westberg]

Changeset: fe273afe
Author:    Robin Westberg <rwestberg at openjdk.org>
Date:      2019-11-26 08:46:57 +0000
URL:       https://git.openjdk.java.net/skara/commit/fe273afe

Switch to GitHub's new review comment positioning API

Reviewed-by: ehelin

! bots/mlbridge/src/main/java/org/openjdk/skara/bots/mlbridge/ReviewArchive.java
! forge/src/main/java/org/openjdk/skara/forge/github/GitHubPullRequest.java
! forge/src/main/java/org/openjdk/skara/forge/github/GitHubRepository.java
- forge/src/main/java/org/openjdk/skara/forge/github/PositionMapper.java
- forge/src/test/java/org/openjdk/skara/forge/github/PositionMapperTests.java