playground: update deployment instructions, move sandbox under "sandbox"

module.

Change-Id: I6a5ff2b6fbc50c968e383df75239045ba2710c87
Reviewed-on: https://go-review.googlesource.com/13811
Reviewed-by: Andrew Gerrand <adg@golang.org>

README.md

diff --git a/README.md b/README.md
index 6199ae4..162b7d6 100644
--- a/README.md
+++ b/README.md
@@ -28,10 +28,12 @@
 ## managed-vms
 
 ```
-boot2docker shellinit
-gcloud preview app setup-managed-vms
-gcloud preview app run app/ sandbox/
-gcloud preview app deploy app/ sandbox/
+gcloud preview app run app/app.yaml
+gcloud preview app run sandbox/app.yaml
+
+gcloud config set project golang-org
+gcloud preview app deploy app/app.yaml --version play
+gcloud preview app deploy sandbox/app.yaml --set-default
 ```
 
 ## kubernetes

sandbox/app.yaml

diff --git a/sandbox/app.yaml b/sandbox/app.yaml
index 0429b7f..cf9e256 100644
--- a/sandbox/app.yaml
+++ b/sandbox/app.yaml
@@ -1,8 +1,8 @@
 application: golang-org
-version: sandbox
 runtime: custom
 api_version: go1
 vm: true
+module: sandbox
 
 manual_scaling:
   instances: 5