Speed up unit tests #113

By now, the whole test suite takes a non-trivial amount of time to run. Partly this is because code coverage is always computed (assuming XDebug is installed, which is itself a source of slowdown), but tests which make use of password_hash() and password_verify()---as well as tests which parse feeds---incur significant delays from sha-256 hashing. Tearing down the database schema and re-creating it for each and every database test probably contributes as well (though this is probably offset somewhat by using an in-memory database).

All these problems can be worked around, but would require increasingly esoteric PHP extension dependencies for anyone wishing to hack on the server. It would also require time and effort to profile and actually tune the slower tests.

Another way to speed up unit tests would be to use atoum (which can run tests in parallel) rather than PHPUnit. This would mean rewriting most of our ~500 tests, however.

For various reasons, Atoum seems not to be any faster than PHPUnit, and is actually slower by a significant amount in a limited test run.

Thus far testing times have gone from:

With coverage: 1:13
Without coverage: 0:27
With fixed timeout test: 0:23

Disabling Xdebug entirely seems to cut off another 10s, but disabling it for testing and enabling it for coverage may get a bit hairy. It may be worth doing either way, as it would be useful to fully control loaded extensions during testing.