Simple unit test

tests/NoCaptchaTest.php

+<?php
+
+use Anhskohbo\NoCaptcha\NoCaptcha;
+
+class NoCaptchaTest extends PHPUnit_Framework_TestCase
+{
+    private $captcha;
+
+    public function setUp()
+    {
+        parent::setUp();
+        $this->captcha = new NoCaptcha('{secret-key}', '{site-key}');
+    }
+
+    public function testDisplay()
+    {
+        $this->assertTrue($this->captcha instanceof NoCaptcha);
+
+        $simple ='<script src="https://www.google.com/recaptcha/api.js" async defer></script>'."\n".
+            '<div class="g-recaptcha" data-sitekey="{site-key}"></div>';
+
+        $withLang ='<script src="https://www.google.com/recaptcha/api.js?hl=vi" async defer></script>'."\n".
+            '<div class="g-recaptcha" data-sitekey="{site-key}"></div>';
+
+        $withAttrs ='<script src="https://www.google.com/recaptcha/api.js" async defer></script>'."\n".
+            '<div class="g-recaptcha" data-theme="light" data-sitekey="{site-key}"></div>';
+
+        $this->assertEquals($this->captcha->display(), $simple);
+        $this->assertEquals($this->captcha->display([], 'vi'), $withLang);
+        $this->assertEquals($this->captcha->display(['data-theme' => 'light']), $withAttrs);
+    }
+}