update Tasks Sample for App Engine [(#1541)](GoogleCloudPlatform/python-docs-samples#1541)

* update gcloud command for creating queues

* deploys and runs

* update license

* passing tests

Author: averikitsch

samples/snippets/README.md

@@ -28,7 +28,7 @@ To set up authentication, please refer to our
 
 To create a queue using the Cloud SDK, use the following gcloud command:
 
-    gcloud alpha tasks queues create-pull-queue my-pull-queue
+    gcloud alpha tasks queues create pull my-pull-queue
 
 ## Running the Samples