update testing infrastructure

[perarnau]

The current unit tests are often lacking in verbosity, which prevent efficient debugging when something goes wrong on a platform we don't control. We should make improvements there, maybe using libcheck for the entire test suite.

There's value in a lot of the tests we do, as a means to validate the platform somehow, but I think this should be better served by writing an aml binary that explores some of the details of the architecture at runtime, instead of a suite of unit tests for the lib.