MAPG-101 add migrations folder structure and create first migration

database/migrations/data/20200602_2306_migrations.php

@@ -0,0 +1 @@
+<?php //empty on purpose

database/migrations/structure/20200602_2306_migrations.sql

@@ -0,0 +1,6 @@
+CREATE TABLE `migrations` (
+  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
+  `migration` varchar(255) NOT NULL,
+  `type` enum('structure', 'data') NOT NULL,
+  PRIMARY KEY (`id`)
+) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4;