Skip or solo tests

[Wolf]

I'm thinking maybe we could introduce a three element array test expectation where the first string is a modifier string for tests that want to use this feature:

export default {
  namespace: {
    normal: [true, true],
    skipped: ["skip", true, false],
    solo: ["only", false, false]
  }
}

Eventually this could also grow to encompass #1 with strings for assertions other than deep equals.

What say ye?