Add Environment Guide example.

This example shows a simple two tier setup in Kubernetes, and
simply prints the environment information that each pod sees.
Querying the service multiple times will show services at work
load balancing requests.

examples/environment-guide/backend-srv.yaml

@@ -0,0 +1,13 @@
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: backend-srv
+  labels:
+    type: backend-type
+spec:
+  ports:
+  - port: 5000
+    protocol: TCP
+  selector:
+    type: backend-type