Add database migration script.

index.php

@@ -11,8 +11,7 @@ if (php_sapi_name() !== 'cli') {
 $capsule = new Capsule;
 $capsule->addConnection([
     'driver' => 'sqlite',
-    'database' => __DIR__ . '/database.sample.sqlite',
-    'prefix' => '',
+    'database' => __DIR__ . '/database.sqlite',
 ]);
 $capsule->setAsGlobal();
 $client = new GuzzleHttp\Client();