In 3.0, unittest's output has become line buffered.  Instead of printing
the test name when it starts a test, then "ok" when it finishes, the
test name is delayed until the "ok" is printed.  This makes it
unnecessarily hard to determine which test is hanging or segfaulted.

The attached patch adds explicit flushes.

An alternative approach would be to force stdout to be unbuffered
somehow.  I don't know how difficult that would be.