Added Support for Token Authorization

[MikeSQ]

On the wiki it appears to support either the global API key or custom API tokens. We tried creating a custom token that I have confirmed works using postman, however it does not work when we use it in the plugin.

Looking at the code, it appears to only support the api key method which requires a Key/Email combination and does not use the Authorization header that the tokens use.

        private Dictionary<string, string> GetCustomHeaders(Settings moduleSettings)
        {
            var newHeaders = new Dictionary<string, string>
            {
                {"X-Auth-Key", moduleSettings.ApiToken}, 
                {"X-Auth-Email", moduleSettings.Email}
            };

            return newHeaders;
        }

Am I missing something? If it weren't for the docs I would have assumed it doesn't currently support the token method, however since the docs not only mention the token method but recommend it I feel like I've missed something obvious.

[WillStrohl]

I didn't fully look into the other method of authorization in this one. Nice find and PR. Thanks!