This PR includes a new package called testrouting, which implements a very algorithmically slow but hopefully easy-to-keep-operationally-correct in-memory routing table. The routing table also supports writing out its current structure as a DOT graph for visualization. testrouting is primarily meant to help in coming up with generic routing table integration tests.
This PR also includes a new routing table integration test suite that runs against all current routing table implementations. Our existing routing table passes a lot of the tests, but not all of them, still debugging why. I have confirmed the tests should pass with the visualization graphs though.