Fix Repo.__repr__ when subclassed

Author: jan-matejka

git/repo/base.py

@@ -1064,7 +1064,8 @@ def has_separate_working_tree(self):
     rev_parse = rev_parse
 
     def __repr__(self):
-        return '<git.Repo "%s">' % self.git_dir
+        clazz = self.__class__
+        return '<%s.%s %r>' % (clazz.__module__, clazz.__name__, self.git_dir)
 
     def currently_rebasing_on(self):
         """