add phpunit

tests/TestCaseBase.php

@@ -0,0 +1,20 @@
+<?php
+/**
+ * Created by PhpStorm.
+ * User: x
+ * Date: 2018/12/9
+ * Time: 11:43 PM
+ */
+
+namespace Tests;
+
+
+use PHPUnit\Framework\TestCase;
+
+class TestCaseBase extends TestCase
+{
+    public function getSnippet($name)
+    {
+        return file_get_contents(__DIR__.'/assets/'.$name.'.html');
+    }
+}