Merge pull request #5 from petfinder-com/feature/sdk-usage-header

update header used to track sdk usage

Author: pftjtn

src/Http/Builder.php

@@ -44,7 +44,7 @@ public function __construct(
     ) {
         $this->http = $httpClient ?? HttpAsyncClientDiscovery::find();
         $this->requestFactory = $requestFactory ?? MessageFactoryDiscovery::find();
-        $this->headers['User-Agent'] = 'petfinder-php-sdk/v1.0 (https://github.com/petfinder-com/petfinder-php-sdk)';
+        $this->headers['X-Api-Sdk'] = 'petfinder-php-sdk/v1.0 (https://github.com/petfinder-com/petfinder-php-sdk)';
     }
 
     public function getHttpClient(): HttpAsyncClient

tests/Http/BuilderTest.php

@@ -120,7 +120,7 @@ public function testHeaders(): void
         $this->builder->getHttpClient()->sendAsyncRequest(new Request('GET', '/test'));
         $this->assertEquals('bar', $this->http->getLastRequest()->getHeaderLine('X-Foo'));
         $this->assertEquals('foo', $this->http->getLastRequest()->getHeaderLine('X-Bar'));
-        $this->assertEquals('petfinder-php-sdk/v1.0 (https://github.com/petfinder-com/petfinder-php-sdk)', $this->http->getLastRequest()->getHeaderLine('User-Agent'));
+        $this->assertEquals('petfinder-php-sdk/v1.0 (https://github.com/petfinder-com/petfinder-php-sdk)', $this->http->getLastRequest()->getHeaderLine('X-Api-Sdk'));
 
         $this->builder->addHeaders(['X-Baz' => 'baz']);