Set up environment for CI

phpcs-errors:0 phpunit-status:successful

tests/startPageTest.php

@@ -0,0 +1,29 @@
+<?PHP
+/**
+ * This script contains tests for the home page.
+ *
+ * @author Joshua Ramon Enslin <joshua@jrenslin.de>
+ */
+declare(strict_types=1);
+
+// phpcs:disable
+
+use PHPUnit\Framework\TestCase;
+
+final class StartPageTest extends TestCase {
+
+    public function testHTMLOutput():void {
+
+        include __DIR__ . "/../index.php";
+        $output = $this->getActualOutput();
+
+        $this->assertEquals(
+            true,
+            is_string($output)
+        );
+
+        ob_clean();
+
+    }
+
+}