Implement outstanding-tasks healthcheck

Mark an instance as healthy when all outstanding tasks (pending &
in-flight) have been completed across all sources. When a repo
filter is specified, then only the replication tasks that correspond
to the repos configured in the filter are checked.

Bug: Issue 312895374
Change-Id: Ia12ace9179860cd96fbdd81488aa2834f8ab29d6
9 files changed
tree: 88910221194f9a42650a8e21bb01766e72e9044f
  1. example-setup/
  2. src/
  3. .gitignore
  4. BUILD
  5. Jenkinsfile
  6. LICENSE