expose Resource class through __all__

Author: cipz

googleapiclient/discovery.py

@@ -19,7 +19,7 @@
 from __future__ import absolute_import
 
 __author__ = "[email protected] (Joe Gregorio)"
-__all__ = ["build", "build_from_document", "fix_method_name", "key2param"]
+__all__ = ["build", "build_from_document", "fix_method_name", "key2param", "Resource"]
 
 from collections import OrderedDict
 import collections.abc