Pymagento

* Add support for environment variables as a fallback for `Magento()` arguments: `PYMAGENTO_TOKEN`, `PYMAGENTO_BASE_URL`
, `PYMAGENTO_SCOPE`, `PYMAGENTO_USER_AGENT`
* Fix `user_agent` support ([`api-session` 1.1.1][as111])

[as111]: https://github.com/Bixoto/api-session/blob/main/CHANGELOG.md#111-20220204

* Add `get_base_prices`
* Fix `get_special_prices` that was throwing an error when `read_only` was true

* Add `save_product_media`, `delete_product_media`, `save_configurable_product_option`, `save_base_prices`,
`get_special_prices`, `save_special_prices`, `delete_special_prices`, `delete_special_prices_by_sku`,
`create_category`, `ship_order`
* Minor type hints improvements

First public release.