Support tagging or WIP tests

[gtrogers]

Sometimes it's nice to be able to write and commit tests that don't pass yet and not have them fail the build.

This could be achieved by either

notion("one day things will be better", function ()
    -- test code goes here
end, {"some", "tags"})

or...

wip_notion("one day things will be better", function ()
    -- test code goes here
end)

Where we find a suitably cute name for wip_notion... maybe whimsy?

Either way we'd need to add an additional overloaded argument to love.