The unit test `test_match_consecutive_timed_frames_in_leaky_mode` has been
removed because it depends on the machine where it is run. Even setting a
high fps and a low "lateness" for images to be dropped, it is still not
enough to make sure it is going to pass in a powerfull computer.

Instead, the test `test_match_timed_frame` has been renamed as
`test_match_consecutive_timed_frames` and modified so that it actually
tests that process_all_frames makes it possible to process every single
frame.