Add firewall access rules endpoint (#37)

* Add firewall access rules endpoint

* Configuration is an object

Maybe this needs to be defined in a seperate namespace (e.g. Cloudflare\API\Configuration) because it's no longer an array.

* Incorporate review

src/Configurations/AccessRules.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace Cloudflare\API\Configurations;
+
+class AccessRules implements Configurations
+{
+    private $config;
+
+    public function setIP(string $value)
+    {
+        $this->config = ['target' => 'ip', 'value' => $value];
+    }
+
+    public function setIPRange(string $value)
+    {
+        $this->config = ['target' => 'ip_range', 'value' => $value];
+    }
+
+    public function setCountry(string $value)
+    {
+        $this->config = ['target' => 'country', 'value' => $value];
+    }
+
+    public function getArray(): array
+    {
+        return $this->config;
+    }
+}