Added local MaxMind country database support

[8ctopus]

First of all, thank you for a great package.

For a project, I'm presently working on, we want to use only local data, so we are using the MaxMind mmdb files. I successfully extended your package in order use the much smaller Maxmind Country database when city location is not required. The database footprint is significantly reduced from 66Mb to 5.6Mb.

All existing tests are successful, however I didn't add any new test as I don't know how to download the MaxMind files for the tests.

[stevebauman]

Thanks for the great PR @8ctopus! 🙏 I'll have a release out shortly.

[8ctopus]

Thank you for accepting my suggestions. Do you happen to know how we could test the local MaxMind databases? It would be good that this gets tested as well.

[stevebauman]

We could file_get_contents() to download it in the test environment and then run some tests using it (as long as there's a direct download somewhere). Otherwise we could store the country database in a tests/fixtures folder (this folder won't be downloaded when installed via composer.

What do you think?

[stevebauman]

I found their test databases that we can use (🎉 ) https://github.com/maxmind/MaxMind-DB

These are pretty small, so I'll download some of their databases (in test-data) and then use it for the tests 👍

[8ctopus]

Great! Thank you for the explanation. I will update the README tomorrow for the country database and can help finishing the tests once you did setup the base.