Gios

Changelog:
- add type annotations
- fix `latitude` and `longitude` properties type **BREAKING CHANGE**
- rename `update` method to `async_method` **BREAKING CHANGE**
- return data from `async_update` method & remove `data` property **BREAKING CHANGE**
- convert data dict keys to lowercase **BREAKING CHANGE**

Changelog:
- update `MANIFEST.in` file

Changelog:
- remove `available` property **BRAKING CHANGE**
- improve tests
- improve logging
- add mypy to CI

Changelog:
- fix `pylint` errors
- add Python 3.9 to CI

Changelog:
- add MANIFEST.in file
- use `patch` from `unittest.mock`

Changelog:
- refactoring data fetch from the server