find: cache path item ids (#286)

Author: skshetry

Diff for: pydrive2/fs/spec.py

@@ -473,6 +473,11 @@ def find(self, path, detail=False, **kwargs):
         bucket, base = self.split_path(path)
 
         seen_paths = set()
+        cached = base in self._ids_cache["dirs"]
+        if not cached:
+            dir_ids = self._path_to_item_ids(base)
+            self._cache_path_id(base, *dir_ids)
+
         dir_ids = [self._ids_cache["ids"].copy()]
         contents = []
         while dir_ids: