Add new class create methods for proper phpunit testing

instead of direct calling Client class and AWS class add a wrapper
method to call those so we can quicker replace under elements and also
do proper testing

src/AWS/AWS.php

@@ -129,6 +129,16 @@ class AWS
 		return new CreateBalanceResponse($result);
 	}
 
+	/**
+	 * return a new curl connection client class
+	 *
+	 * @return Client Curl connection Client
+	 */
+	public function newClient(): Client
+	{
+		return new Client();
+	}
+
 	/**
 	 * General request method for all actions
 	 * Calls the Client class that actually runs the json request
@@ -190,7 +200,7 @@ class AWS
 			$date_time_string,
 			$service_target
 		);
-		return (new Client())->request($url, $headers, $payload);
+		return ($this->newClient())->request($url, $headers, $payload);
 	}
 
 	/**

src/AmazonIncentives.php

@@ -67,7 +67,7 @@ final class AmazonIncentives
 	 */
 	public function buyGiftCard(float $value, string $creation_request_id = null): Response\CreateResponse
 	{
-		return (new AWS($this->config))->getCode($value, $creation_request_id);
+		return ($this->newAWS())->getCode($value, $creation_request_id);
 	}
 
 
@@ -82,7 +82,7 @@ final class AmazonIncentives
 	 */
 	public function cancelGiftCard(string $creation_request_id, string $gift_card_id): Response\CancelResponse
 	{
-		return (new AWS($this->config))->cancelCode($creation_request_id, $gift_card_id);
+		return ($this->newAWS())->cancelCode($creation_request_id, $gift_card_id);
 	}
 
 	/**
@@ -94,7 +94,7 @@ final class AmazonIncentives
 	 */
 	public function getAvailableFunds(): Response\CreateBalanceResponse
 	{
-		return (new AWS($this->config))->getBalance();
+		return ($this->newAWS())->getBalance();
 	}
 
 	/**
@@ -119,6 +119,17 @@ final class AmazonIncentives
 		return new static($key, $secret, $partner, $endpoint, $currency, $debug);
 	}
 
+	/**
+	 * wrapper to create new AWS class.
+	 * used in all buy/cancel/get calss
+	 *
+	 * @return AWS Main AWS worker class
+	 */
+	public function newAWS(): AWS
+	{
+		return new AWS($this->config);
+	}
+
 	/**
 	 * Decodes the Exception message body
 	 * Returns an array with code (Amazon error codes), type (Amazon error info)