fix: correct content-type headers on typed function response (GoogleCloudPlatform#152)

Author: garethgeorge

Diff for: src/TypedFunctionWrapper.php

@@ -99,6 +99,6 @@ public function execute(ServerRequestInterface $request): ResponseInterface
         }
         $resultJson = $funcResult->serializeToJsonString();
 
-        return new Response(200, ['content-type' => 'application/cloudevents+json'], $resultJson);
+        return new Response(200, ['content-type' => 'application/json'], $resultJson);
     }
 }

Diff for: tests/TypedFunctionWrapperTest.php

@@ -109,6 +109,7 @@ function (IntValue $foo): IntValue {
         $request = new ServerRequest('POST', '/', ['content-type' => 'application/json'], '1');
         $response = $typedFunctionWrapper->execute($request);
         $this->assertSame('2', (string) $response->getBody());
+        $this->assertSame('application/json', $response->getHeaderLine("Content-Type"));
     }
 
     public function testBadRequest(): void