Install ruby whenever it isn't already present

Author: dsabeti

bin/run

@@ -93,16 +93,14 @@ function main() {
   local phase
   phase="$(basename "${0}")"
 
-  if [[ "${CF_STACK:-}" != "cflinuxfs3" ]]; then
-    if ! which ruby > /dev/null; then
-      mkdir -p "${RUBY_DIR}"
-
-      util::install
-    fi
+  if ! which ruby > /dev/null; then
+    mkdir -p "${RUBY_DIR}"
 
+    util::install
     util::environment::setup
   fi
 
+
   exec "${BUILDPACK_DIR}/bin/ruby-run" "${phase}" "${@-}"
 }