added enum for sort

src/enums/SortEnum.php

@@ -0,0 +1,18 @@
+<?php
+/**
+ * Created by PhpStorm.
+ * User: sgorzaly
+ * Date: 22.02.18
+ * Time: 20:24
+ */
+
+namespace ParseCsv\enums;
+
+
+class SortEnum {
+    const SORT_TYPE_REGULAR = SORT_REGULAR;
+
+    const SORT_TYPE_NUMERIC = SORT_NUMERIC;
+
+    const SORT_TYPE_STRING = SORT_STRING;
+}