New feature suggestion: test.quiet

[JohnForster]

Sometimes I want tests to run and fail as normal, but I don't need to see the output of why they failed every time I run my test. Often the output of these failing tests clutters the terminal and makes it harder to spot exactly what I'm looking for in other tests. I suggest an option test.quiet, similar to test.skip, which runs the test as normal, but does not output failed exceptions to the terminal, instead just being included in the summary.

There could be an equivalent test.loud which corresponds to test.only, putting all other tests into "quiet" mode.