In legacy/trac#27912, we configure a bunch of deb lines that depend on deb.torproject.org. But what happens when the repository is updated after a release? We can either: * remember to update the travis config every release, or * work out how to make the jobs fail when they fall back to 0.2.9.14 (or Ubuntu security updates' current version) Maybe there's a travis option that we could use? This task does not need to be solved straight away.