Add some semblance of testing.

tests/ConfigurationTest.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace tests\FooBar;
+
+use FooBar\Configuration;
+use PHPUnit\Framework\TestCase;
+
+class ConfigurationTest extends TestCase
+{
+    public function testDefaultSecurity()
+    {
+        $config = $this->getSampleConfig();
+
+        $this->assertTrue($config->isAuthorized('127.0.0.1'));
+        $this->assertFalse($config->isAuthorized('8.8.8.8'));
+    }
+
+    public function testLoadConfig()
+    {
+        $this->assertNotNull(Configuration::loadConfig());
+    }
+
+    private function getSampleConfig(): Configuration
+    {
+        $path = dirname(__DIR__) . '/config/config.sample.php';
+
+        return new Configuration(require $path);
+    }
+}