We want to be able to run:

1. the test suites (make test) of all Python modules, and
2. static code checks (make check)

every time we push a commit to any monitored repository.

To trigger rebuilds we can use Phabricator's Harbormaster application.
But right now the only build action that Harbormaster is capable of is submitting an HTTP request to some external build tool. So to implement this we will first need to setup something like Jenkins, or simpler ad hoc tooling that can be triggered via HTTP.