ignore attributes of function arguments.

[younata]

If I have a protocol that has:

func geocode(query: String, callback: @escaping (MKLocalSearchResponse?, Error?) -> (Void)) -> (Void)

I should not see stuff like:

func geocodeArgs(forCall callIndex: Int) -> (String, @escaping (MKLocalSearchResponse?, Error?) -> (Void)) {
        return self.geocodeArgs[callIndex]
    }

in my generated fake