Fix test for foldrDefault (#79)
Fix test for foldrDefault (#79)

* Fix test for foldrDefault

The test labelled "Test foldrDefault" was calling the function to test
fold*l*Default (`testFoldableFoldlDefault`). The test for
foldrDefault (`testFoldableFoldrDefault`) was never called.
LiamGoodacre/purescript-foldable-traversable,purescript/purescript-foldable-traversable