2023-02-22 -- Migrate tests to 'pytest'.

2021-11-07 -- Use isbnlib-3.10.9+ to reflect changes in external serv…

…ices.

2021-04-13 -- Fix 'deleted imports'.

2021-04-13 -- Improved speed with isbnlib-3.10.7.

2021-01-26 -- Fix py27 issues and close issue #106.

2020-12-31 -- Check pypi services response.

2020-05-18 -- Add the option to NOT load plugins.

2020-03-26 -- Add 'classify'.

2020-01-15 -- Better data quality with isbnlib-3.9.10+.

2019-05-14 -- Add 'get/set' to 'ShelveCache'.