Add configuration to skip tests

[brynrhodes]

There should be a "skip" input parameter that takes a list of names of tests to be skipped.

[darkknight13]

Will there be an option to skip by tests, by group, or by a test only? If we intend to support skipping by tests and by group, in addition to skipping a test, should we use the same parameter "skip" or separate parameters such as "skip-tests", "skip-group", and "skip-test"? Alternatively, another option could be to allow anything to be passed to the "skip" parameter—tests, groups, or test names—and if it matches anything, it will be skipped.

[richfirely]

I added some functionality like this in the linked PR. I had to get past some tests during development of said PR. Hopefully it's easily adjusted to account for ideas here. For the moment it takes all 3, tests, group, test.