Python: user assertions without messages are too silent

[Expurple]

When solution contains an assert statement (simple form, without a message) and that assert fails, tests are aborted without any error messages at all. It's hard to understand what's going on.

To reproduce: train on any Python kata, submit a function with assert False in its body. Compare with assert False, "User assertion failed".

I'm not sure what can/should be done here, but it just felt very confusing, I had to debug my solution locally. I often add asserts to find bugs early. Without messages, of course. Initially I expected a full traceback, like from raise RuntimeError(). That would be very useful for debugging without a local IDE. But it looks like AssertionError is used by the test framework, so it's displayed differently.

[Blind4Basics]

same as #13, isn't it?