• Added google.oauth2.credentials.Credentials.from_authorized_user_file (#226)
• Dropped direct pyasn1 dependency in favor of letting pyasn1-modules specify the right version. (#230)
• default() now checks for the project ID environment var before warning about missing project ID. (#227)
• Fixed the docstrings for has_scopes() and with_scopes(). (#228)
• Fixed example in docstring for ReadOnlyScoped. (#219)
• Made transport.requests use timeouts and retries to improve reliability. (#220)