function apiAuthorizer(username, password, callback) {
    // API Rate Limit
    apiRateLimiter.pass(null, 0).then((pass) => {
        if (pass) {
            verifyAPIKey(password).then((valid) => {
                if (!valid) {
                    log.warn("api-auth", "Failed API auth attempt: invalid API Key");
                }
                callback(null, valid);
                // Only allow a set number of api requests per minute
                // (currently set to 60)
                apiRateLimiter.removeTokens(1);
            });
        } else {
            log.warn("api-auth", "Failed API auth attempt: rate limit exceeded");
            callback(null, false);
        }
    });
}
Custom authorizer for express-basic-auth
@param {string} username Username to login with
@param {string} password Password to login with
@param {authCallback} callback Callback to handle login result
@returns {void}