Revision history for Google::ContentAPI.

1.03 2020-12-10 Added support for Google Content API for Shopping v2.1 via new
                'endpoint' attribute. If endpoint attribute not provided, defaults
                to v2.0 endpoint for backwards compatibility. Google::ContentAPI
                is code compatible with both v2.0 and v2.1 endpoints.

                You may need to update your application to account for several
                breaking changes introduced in v2.1. Review to Google's migration document,
                "Migrating from Content API v2 to v2.1" at
                https://developers.google.com/shopping-content/guides/migration

1.02  2018-04-11 Added accountstatuses and productstatuses methods. Also added 
                 a "custom" resource to perform methods that are not implemented 
                 by this module.

1.01  2018-03-27 Added config_json, merchant_id options.
                 Switched to Crypt::JWT on recommendation of Andrew Maltsev, as
                 it is a more stable module and is likely to be installed already.

1.00  2018-03-23 initial implementation