Add README file, add status to exception return

Because status RESEND/FAILURE has to be checked we also add this to the
Exception return json string.
Also handle unset errors (eg when we get an Rate Limit error)

Move the _ENV check into mtheod

test now has some basic mock tests

src/Amazon/Exceptions/AmazonErrors.php

@@ -7,13 +7,15 @@ use RuntimeException;
 class AmazonErrors extends RuntimeException
 {
 	/**
-	 * @param  string $error_code  errorCode from Amazon
-	 * @param  string $error_type  errorType from Amazon
+	 * @param  string $error_status agcodResponse->status from Amazon
+	 * @param  string $error_code   errorCode from Amazon
+	 * @param  string $error_type   errorType from Amazon
 	 * @param  string $message
 	 * @param  string $_error_code
 	 * @return AmazonErrors
 	 */
 	public static function getError(
+		string $error_status,
 		string $error_code,
 		string $error_type,
 		string $message,
@@ -22,6 +24,7 @@ class AmazonErrors extends RuntimeException
 		// NOTE: if xdebug.show_exception_trace is set to 1 this will print ERRORS
 		return new static(
 			json_encode([
+				'status' => $error_status,
 				'code' => $error_code,
 				'type' => $error_type,
 				'message' => $message,