CHEF-4327: Directory resource failing because of incorrect version of FFI

Basic issue seems to be that the pre-release version of 11.6 is including ffi 1.9.0 -- this is known to break Chef (we need to stay at 1.3.1). Ominbus-chef configuration pins these versions, but because this is a pre-release build, other gems pull down first end up pulling these latest prerequisites. This fix includes the pinned versions first so that dependencies are satisfied with the right versions.