I think it would be good to have a special "ignore if" decorator for tests like this that take a long time, so that they can be excluded when desired. Or a "fast test" mode, where the test only runs on a representative sample of the exercises (specifically targeting those that may have problems). Any suggestions for approaches to this, @bcipolli?

The continuous integration server would still run the full thing, but for running locally, the quick version could be run. Otherwise, if the testing takes 30 mins, it's not going to be run locally anyway...