add config phpunit test

Tests/ConfigurationTest.php

@@ -0,0 +1,25 @@
+<?php
+/**
+ * Created by Pavel Popov
+ */
+
+namespace Metaer\CurlWrapperBundle\Tests;
+
+
+use Metaer\CurlWrapperBundle\DependencyInjection\Configuration;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Config\Definition\Processor;
+
+class ConfigurationTest extends TestCase
+{
+    public function testConfiguration() {
+        $config = [];
+
+        $processor = new Processor();
+        $configuration = new Configuration();
+        $config = $processor->processConfiguration($configuration, [$config]);
+
+        $this->assertArrayHasKey('wrapper', $config);
+        $this->assertEquals('metaer_curl_wrapper.curl_wrapper.default', $config['wrapper']);
+    }
+}