Add Benin Holidays

[Massoud114]

Contributing a new country ?

• Yes, I've checked, and there is no current PR for Benin. I had already opened one and it was closed.

1. Create a new class in the Countries directory. It should extend the Country class.
2. Add a test for the new country in the tests directory.
3. Run the tests so a snapshot gets created.
4. Verify the result in the newly created snapshot is correct.

[Nielsvanpach]

Results seem to be wrong? Have you checked all results in the snapshot?

[Massoud114]

The content of the snapshot is badly encoded for French characters (é,è,ê...), I don't know how to fix it.

[Nielsvanpach]

Thanks!