First set of data mappers.

app/Import/Mapper/MapperInterface.php

@@ -0,0 +1,26 @@
+<?php
+/**
+ * MapperInterface.php
+ * Copyright (C) 2016 thegrumpydictator@gmail.com
+ *
+ * This software may be modified and distributed under the terms
+ * of the MIT license.  See the LICENSE file for details.
+ */
+
+declare(strict_types = 1);
+
+namespace FireflyIII\Import\Mapper;
+
+/**
+ * Interface MapperInterface
+ *
+ * @package FireflyIII\Import\Mapper
+ */
+interface MapperInterface
+{
+
+    /**
+     * @return array
+     */
+    public function getMap(): array;
+}