Test functions of arity greater than 2

[kmels]

The following function is not being tested

ackermannE :: Int -> Int -> Int
ackermannE m n | m == 0 = n + 1
| m > 0 && n == 0 = ackermann (m-1) 1
| m > 0 && n > 0 = ackermann (m-1) (ackermann m (n-1))
| otherwise = error "undefined"

To reproduce

dart-haskell -f examples/testing/OnInts.hs -t ackermannE

Within output:

main:OnInt.ackermannE => \nakE -> exp