RFR: 437: Skara should invalidate approved reviews if the target branch changes

[Robin Westberg]

Hi all,

Please review this change that disregards pull request reviews done before changing the target branch, as that is not
what's reviewed. Tested manually on GitHub.

Best regards,
Robin

-------------

Commit messages:
 - Ignore reviews done before switching base ref

Changes: https://git.openjdk.java.net/skara/pull/689/files
 Webrev: https://webrevs.openjdk.java.net/skara/689/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/SKARA-437
  Stats: 21 lines in 2 files changed: 20 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/skara/pull/689.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/689/head:pull/689

PR: https://git.openjdk.java.net/skara/pull/689