Merge pull request #41 from buildkite-plugins/toote_fs_recursion

FS backend recursive saves

Author: pzeballos

backends/cache_fs

@@ -11,6 +11,10 @@ restore_cache() {
 save_cache() {
   local to="${CACHE_FOLDER}/$1"
   local from="$2"
+
+  if [ -n "$1" ] && [ -e "$to" ]; then
+    rm -rf "$to"
+  fi
   cp -a "$from" "$to"
 }