Fix typo

Author: Jon Wayne Parrott

packages/google-auth/scripts/obtain_user_auth.py

@@ -17,7 +17,7 @@
 These credentials are needed to run the system test for OAuth2 credentials.
 It's expected that a developer will run this program manually once to obtain
 a refresh token. It's highly recommended to use a Google account created
-specifically created for testing.
+specifically for testing.
 """
 
 import json