When running CI in other repositories (e.g. Docker's downstream
docker/engine repository), or other branches, the validation
scripts were calculating the list of changes based on the wrong
information.
This lead to weird failures in CI in a branch where these values
were not updated ':-) (CI on a pull request failed because it detected
that new tests were added to the deprecated `integration-cli` test-suite,
but the pull request did not actually make changes in that area).
This patch allows overriding the target repository (and branch)
to compare to (without having to edit the scripts).
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2a08f33166