优化测试，文件读取测试

src/Exception/FileNotFoundException.php

@@ -0,0 +1,17 @@
+<?php
+/**
+ * @filename FileNotFoundException.php
+ * @author Jerry Yan <792602257@qq.com>
+ * @date 2021/1/26 13:52
+ */
+
+
+namespace JerryYan\DSL\Exception;
+
+
+use Exception;
+
+class FileNotFoundException extends Exception
+{
+
+}