Major update, add renew command, rename register to setup

src/functions.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Kelunik\AcmeClient;
+
+function commandToClass(string $command): string {
+    return __NAMESPACE__ . "\\Commands\\" . ucfirst($command);
+}
+
+function getServer(Configuration $config = null) {
+    if ($config === null) {
+        $path = dirname(__DIR__) . "/data";
+        $config = new Configuration($path . "/account/config.json");
+    }
+
+    return $config->get("server");
+}