Add options to skip tests.

[bennyturns]

Skip small file, large file, metadata or any combination of the three.

[ShyamsundarR]

This is useful to have, but we would need a default test to be present in the script (which I would guess we would have). As the intention of the test is to repeat the same test across runs. If we change the defaults, then we should ideally not be reporting the results against this test, but a test+config that was used to configure this test.