Add base gateway test setup, update tests dependency

Author: leith

composer.json

@@ -46,7 +46,7 @@
         "php": "^7.2||^8"
     },
     "require-dev": {
-        "omnipay/tests": "^4.1",
+        "omnipay/tests": "^4.2",
         "squizlabs/php_codesniffer": "^3.5",
         "http-interop/http-factory-guzzle": "^1.1"
     },

tests/GatewayTest.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace Omnipay\WindcaveHpp;
+
+use Omnipay\Tests\GatewayTestCase;
+
+class GatewayTest extends GatewayTestCase
+{
+    /** @var array */
+    protected $options;
+
+    public function setUp(): void
+    {
+        parent::setUp();
+
+        $this->gateway = new Gateway($this->getHttpClient(), $this->getHttpRequest());
+
+        $this->options = [
+            'amount'        => '1.45',
+            'apiUsername'   => 'Test_Merchant',
+            'apiKey'        => 'ABCDEF1234567890ABCDEF1234567890ABCDEF1234567890ABCDEF1234567890',
+            'currency'      => 'NZD',
+            'cancelUrl'     => 'https://www.example.com/cancel',
+            'notifyUrl'     => 'https://www.example.com/notify',
+            'returnUrl'     => 'https://www.example.com/return',
+            'transactionId' => '123abc',
+            'testMode'      => true,
+        ];
+    }
+}