Add REST API endpoint for all downstream branches.

In addition to having an endpoint telling us what branches are a single
automerger downstream hop down, we also have an endpoint telling us all
the branches that are downstream of a given branch.

Change-Id: Ie839e1dd8e9764b9134478569f5c9024efbea285
5 files changed
tree: a3745b1ef55f807d3a24c62fdb0f383b0ff10b5f
  1. src/
  2. .gitignore
  3. BUILD
  4. external_plugin_deps.bzl
  5. LICENSE
  6. LICENSE-re2j