Plugin broken due to authentication change (API Key deprecated by Gandi)

[m0nkeyc0de]

Hello, This plugin is currently broken as it uses the deprecated authentication scheme with with the API Key, according to the official documentation.

In order to fix that, the "_headers" function must be modified as follows (replace Apikey with Bearer):

def _headers(cfg):
    return {
        'Content-Type': 'application/json',
        'Authorization': 'Bearer ' + cfg.api_key
    }