Ok fixes (#198)

* getHttpHeaders function added

* Function updated to allow nullable request

* Function updated to allow nullable request

* Fixes to pass tests in accordance with respective request class

* fixes failure "Iyzipay\Tests\Request\CreateBasicBkmInitializeRequestTest::test_should_get_json_object"

* fixes failure "6) Iyzipay\Tests\Request\CreateBlacklistedCardRequestTest::test_should_convert_to_pki_request_string"

* fixes failure "7) Iyzipay\Tests\Request\CreateCheckoutFormInitializeRequestTest::test_should_get_json_string"

* fixes failure "8) Iyzipay\Tests\Request\CreateIyziupFormInitializeRequestTest::test_should_get_json_string"

* fixes failure "9) Iyzipay\Tests\Request\CreateIyziupFormInitializeRequestWithInitialConsumerTest::test_should_get_json_string"

* fixes failure "10) Iyzipay\Tests\Request\Subscription\SubscriptionUpgradeRequestTest::test_should_get_json_string"

* fixes failure "11) Iyzipay\Tests\Request\UpdateBlacklistedCardRequestTest::test_should_convert_to_pki_request_string"

* fixes failure "5) Iyzipay\Tests\Request\CreateBasicPaymentRequestTest::test_should_get_json_string"

* fixes failure "6) Iyzipay\Tests\Request\CreateBlacklistedCardRequestTest::test_should_convert_to_pki_request_string"

* fixes failure "1) Iyzipay\Tests\DefaultHttpClientTest::test_should_check_if_options_not_empty"

* fixes error 1 "Call to undefined method..."

* fixes error 2 "file_get_contents/.... Failed to open stream"

* Put, Patch fix

---------

Co-authored-by: Osman Keser <[email protected]>

tests/Iyzipay/Tests/IyzipayResourceTestCase.php

@@ -26,7 +26,7 @@ public function setUp(): void
         parent::setUp();
 
         $this->httpClient = $this->getMockBuilder("HttpClient")
-            ->setMethods(array("get", "getV2","post", "patch", "delete", "exchange"))
+            ->setMethods(array("get", "getV2","post", "put", "patch", "delete", "exchange"))
             ->getMock();
 
         ApiResource::setHttpClient($this->httpClient);