* fdescribe
* fcontext
* fi
* xdescribe
* xcontext
* xit
are valid Quick calls and should not trigger this violation.
There should be another SwiftLint rule to discourage the use of focused
tests, so people don't commit and push code with focused tests.
* Apply 'cheap' validation earlier. It's not a call to a restrictive
method, returns no violations.
* But if it it's a call to a restrictive method, then checks if the file
containts a QuickSpec and if the call is within the bounds of the
QuickSpec class.