test_planner: Add Gerrit API call function

This will let me fetch details about Gerrit change+revisions as part of
replacing the old "build report" idea.

The changes in go.mod are more related to the next CL to come, which
brings in Luci auth and subcommands.

BUG=chromium:922995

Change-Id: I37f463371178649e9c4daea6aaac09d1e01df150
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/test_planner/+/1551648
Tested-by: Sean Abraham <seanabraham@chromium.org>
Trybot-Ready: Sean Abraham <seanabraham@chromium.org>
Reviewed-by: Yaakov Shaul <yshaul@google.com>
Commit-Queue: Sean Abraham <seanabraham@chromium.org>
4 files changed
tree: ca3971c30c85ecc9b9768ffeedeff12df9c09209
  1. src/
  2. .gitignore
  3. cipd.yaml
  4. deploy_cipd.json
  5. deploy_cipd.sh