Derive mode from DSN function

- Add headers in all files
- Minor field name changes

tests/integration/postgresql/CustomTest.php

@@ -1,4 +1,10 @@
-<?php declare(strict_types=1);
+<?php
+/**
+ * @author Daniel J. Summers <daniel@bitbadger.solutions>
+ * @license MIT
+ */
+
+declare(strict_types=1);
 
 namespace Test\Integration\PostgreSQL;