client-go: Add CRUD Deployment sample

This sample adds sample code for create/list/replace/delete operations for
Deployment resource for client-go library. This patch also contains
documentation explaining what the example application does and how it can be
executed.

This patch is part of the body of work improving the client library samples.

Signed-off-by: Ahmet Alp Balkan <ahmetb@google.com>

Kubernetes-commit: d75710f9f4d2e74979f6da07de31b02fae0392b0

examples/create-update-delete-deployment/README.md

@@ -0,0 +1,81 @@
+# Create, Update & Delete Deployment
+
+This example program demonstrates the fundamental operations for managing on
+[Deployment][1] resources, such as `Create`, `List`, `Update` and `Delete`.
+
+You can adopt the source code from this example to write programs that manage
+other types of resources through the Kubernetes API.
+
+## Running this example
+
+Make sure you have a Kubernetes cluster and `kubectl` is configured:
+
+    kubectl get nodes
+
+Compile this example on your workstation:
+
+```
+cd create-update-delete-deployment
+go build -o ./app
+```
+
+Now, run this application on your workstation with your local kubeconfig file:
+
+```
+./app -kubeconfig=$HOME/.kube/config
+```
+
+Running this command will execute the following operations on your cluster:
+
+1. **Create Deployment:** This will create a 2 replica Deployment. Verify with
+   `kubectl get pods`.
+2. **Update Deployment:** This will update the Deployment resource created in
+   previous step to set the replica count to 1 and add annotations. You are
+   encouraged to inspect the retry loop that handles conflicts. Verify the new
+   replica count and `foo=bar` annotation with `kubectl describe deployment
+   demo`.
+3. **List Deployments:** This will retrieve Deployments in the `default`
+   namespace and print their names and replica counts.
+4. **Delete Deployment:** This will delete the Deployment object and its
+   dependent ReplicaSet resource. Verify with `kubectl get deployments`.
+
+Each step is separated by an interactive prompt. You must hit the
+<kbd>Return</kbd> key to proceeed to the next step. You can use these prompts as
+a break to take time to  run `kubectl` and inspect the result of the operations
+executed.
+
+You should see an output like the following:
+
+```
+Creating deployment...
+Created deployment "demo-deployment".
+-> Press Return key to continue.
+
+Updating deployment...
+Updated deployment...
+-> Press Return key to continue.
+
+Listing deployments in namespace "default":
+ * demo-deployment (1 replicas)
+-> Press Return key to continue.
+
+Deleting deployment...
+Deleted deployment.
+```
+
+## Cleanup
+
+Successfully running this program will clean the created artifacts. If you
+terminate the program without completing, you can clean up the created
+deployment with:
+
+    kubectl delete deploy demo-deployment
+
+## Troubleshooting
+
+If you are getting the following error, make sure Kubernetes version of your
+cluster is v1.6 or above in `kubectl version`:
+
+    panic: the server could not find the requested resource
+
+[1]: https://kubernetes.io/docs/user-guide/deployments/