Some more progresss on Cascading

That's weird, it should be this rule that fixes that: https://github.com/Netflix/PigPen/blob/cascading/pigpen-core/src/main/clojure/pigpen/oven.clj#L261

https://github.com/Netflix/PigPen/blob/cascading/pigpen-core/src/test/clojure/pigpen/oven_test.clj#L370