chore: PHP8 support, dependency updates

Converted repository to metapackage

⚙ Added support for Guzzle client and request configuration (#90)

Added missing API endpoints to README.md

Workaroud for Match StaticData linking in case of "None" bans (#75)

Improved CLI --extend flag

Updated Composer dependencies

Centralize access to API keys in tests (should allow PR tests to fina…

…lly work)

v4.0.1 README update

Updated README, re-enabled Travis cache