Initial SQLite development (#1)

Reviewed-on: #1

src/Mapper/CountMapper.php

@@ -0,0 +1,17 @@
+<?php declare(strict_types=1);
+
+namespace BitBadger\PDODocument\Mapper;
+
+/**
+ * A mapper that returns the integer value of the first item in the results
+ */
+class CountMapper implements Mapper
+{
+    /**
+     * @inheritDoc
+     */
+    public function map(array $result): int
+    {
+        return (int) $result[0];
+    }
+}