Transforming tests that use XCTExpectation

[dfed]

If you'd like to add support for transforming tests that utilize XCTExpectation, I just wrote a near drop-in replacement for it here.

Fully understand if this level of complexity (adding a 3rd party dependency & modifying the Package file) isn't something you'd prefer to take on. But I wanted to make you aware of the option 🙂

I'd also be happy to collaborate on making the Expectation in that repo closer to a straight drop-in if you'd like to utilize this package in your plugin.