update tasks samples to support new api version (#83)

Author: bart-at-google

cloud-tasks/createTask.js

@@ -39,12 +39,12 @@ function createTask(project, location, queue, options) {
   const task = {
     appEngineHttpRequest: {
       httpMethod: 'POST',
-      relativeUrl: '/log_payload',
+      relativeUri: '/log_payload',
     },
   };
 
   if (options.payload !== undefined) {
-    task.appEngineHttpRequest.payload = Buffer.from(options.payload).toString(
+    task.appEngineHttpRequest.body = Buffer.from(options.payload).toString(
       'base64'
     );
   }