gcloud app component no longer exists

No longer need to explicitly `gcloud components update app`

Fixes #60

Author: remi Taylor

datastore/README.md

@@ -42,9 +42,6 @@ tool](https://developers.google.com/cloud/sdk/gcloud/) and use it to create the
 indexes used in the tests. From the Datastore samples directory:
 
 ``` sh
-# Install the app component
-$ gcloud components update app
-
 # Set the default project in your env
 $ gcloud config set project PROJECT_ID