Why is not possible to run tests using ':memory:' instead of 'test.db'?

[turicas]

I've replaced 'test.db' with '':memory:'' on flask_peewee/tests/test_config.py but got many errors when trying to run the tests. Is it possible to modify the test suit so we can run all tests way faster using an in-memory database?

For instance, it takes almost 6 minutes to run all tests (python runtests.py) on my machine (Intel Core i5 M 480 @ 2.67GHz, 4GB RAM, running Debian GNU/Linux) - this task is I/O intensive.