Breaking Changes
* The `Virustotal` class now defaults to version 3 of the VirusTotal API.
* Dropped support for `COMPATIBILITY_ENABLED` parameter on the `Virustotal` class.
Docs
* Updated README content including instructions for running tests and improve general readability.
* Moved to using Google docstring format.
* Improved type hints.
* Refactored examples to favour version 3 of the VirusTotal API.
* Added a proper CHANGELOG.
Tests
* Added new unit tests with 95% coverage.
Misc Changes
* `API_VERSION` can now accept an `int` to specify VirusTotal API version to use.
* Add GitHub actions workflows for automated testing and publishing.