--show-skipped tests option

[Sigmanificient]

Hi, it would be nice to add a option to show the number of skipped tests.
This would avoid setting verbose to check for skipped tests.

[====] Synthesis: Tested: 0 | Passing: 0 | Failing: 0 | Crashing: 0 

would become

[====] Synthesis: Tested: 0 | Passing: 0 | Failing: 0 | Crashing: 0 | Skipped: 1

when the flag --show-skipped is set.

[drawbu]

Yeah, I feel like this should be part of Criterion by default, skipped tests are a nice feature, but the fact that we don't see anything make it much less pleasant to use...