Add getResponseCode to response object

Author: jpresutti

FeastTests/HttpRequest/CurlTest.php

@@ -205,7 +205,7 @@ public function testGetResponseCode(): void
         $request->get('https://www.google.com/json');
         $request->makeRequest();
         $response = $request->getResponse();
-        $this->assertEquals(200, $response->getResponseCode());
+        $this->assertEquals(ResponseCode::HTTP_CODE_200, $response->getResponseCode());
         $this->assertNull(
             $request->getResponseAsXml()
         );

HttpRequest/Response.php

@@ -58,7 +58,7 @@ public function getResultAsXml(): ?SimpleXMLElement
         }
     }
 
-    public function getResponseCode(): int
+    public function getResponseCode(): ResponseCode
     {
         return $this->responseCode;
     }