The current compatibility test is pretty minimal, I'd like to see if we can do something better.

Suggestions:

• Instead of testing just the last two releases, could we build and test against the current major releases? I'm suggesting the most recent git tags for mongodb-3.2, mongodb-3.4 and mongodb-4.0, against the develop branch, and against each other, because as we release patches to those releases, we should continue to confirm their compatibility.
• I don't see any reason to configure test/format to configure and run against Berkeley DB, that's not the purpose of this test, so the configure script can be simplified.
• The configuration is pretty simplistic (rows=10000, ops=1000), and turns off things like reverse, (for build simplicity, but I think the expanded testing is worth a little complexity).
• The configuration doesn't test all of the access methods, it only tests one (randomly chosen). I'd like to see a more complex test of each of the access methods on every run.
• I don't think failures are being correctly archived, I think they're getting overwritten by each new test run.