Update Guzzle call in PHP runtime (#20)

* Update example PHP runtime with changes requested by guzzle tool,
  which as of v6 deprecates use of POST'ing body in this way
* Replaced by simply `json_encode()`ing the response payload and
  updating the hello/goodbye example functions to provide array output

Author: matthewpoer

example/function/src/goodbye.php

@@ -5,7 +5,9 @@
 
 function goodbye($data)
 {
-    return "Goodbye, {$data['name']}!";
+    $response = [
+        'msg' => "Goodbye, {$data['name']}!",
+        'data' => $data
+    ];
+    return $response;
 }
-
-?>

example/function/src/hello.php

@@ -5,7 +5,9 @@
 
 function hello($data)
 {
-    return "Hello, {$data['name']}!";
+    $response = [
+        'msg' => "Hello, {$data['name']}!",
+        'data' => $data
+    ];
+    return $response;
 }
-
-?>

example/runtime/bootstrap

@@ -22,8 +22,8 @@ function sendResponse($invocationId, $response)
 {
     $client = new \GuzzleHttp\Client();
     $client->post(
-    'http://' . $_ENV['AWS_LAMBDA_RUNTIME_API'] . '/2018-06-01/runtime/invocation/' . $invocationId . '/response',
-       ['body' => $response]
+      'http://' . $_ENV['AWS_LAMBDA_RUNTIME_API'] . '/2018-06-01/runtime/invocation/' . $invocationId . '/response',
+      ['body' => json_encode($response)]
     );
 }
 
@@ -42,5 +42,3 @@ do {
     // Submit the response back to the runtime API.
     sendResponse($request['invocationId'], $response);
 } while (true);
-
-?>