codeception configs, web config modifed for db-settings

apps/basic/config/codeception/acceptance.php

+<?php
+
+return [];

apps/basic/config/codeception/functional.php

+<?php
+
+return [];

apps/basic/config/codeception/unit.php

+<?php
+
+return [
+	'components' => [
+		'fixture'	=>	[
+			'class'		=>	'yii\test\DbFixtureManager',
+			'basePath'	=>	'@app/tests/unit/fixtures',
+		],
+		'db' => [
+			'dsn' => 'mysql:host=localhost;dbname=yii2basic_unit',
+		],
+	],
+];

apps/basic/config/web.php

 <?php
+
+Yii::setAlias('tests', realpath(__DIR__ . '/../tests'));
+
 $params = require(__DIR__ . '/params.php');
+
 $config = [
 	'id' => 'basic',
 	'basePath' => dirname(__DIR__),
@@ -26,6 +30,13 @@ $config = [
 				],
 			],
 		],
+		'db' => [
+			'class' => 'yii\db\Connection',
+			'dsn' => 'mysql:host=localhost;dbname=yii2basic',
+			'username' => 'root',
+			'password' => '',
+			'charset' => 'utf8',
+		],
 	],
 	'params' => $params,
 ];