Updating Spark Example.

Few usability improvements:

- Added a proxy to enable viewing worker logs
- Removed seperate webui service
- Modified Zeppelin and spark-ui services to be Loadbalancers
- Changed pyspark example to be platform agnostic
- Improved kubectl context setup
- Minor grammar/flow fixes

examples/examples_test.go

@@ -291,13 +291,14 @@ func TestExampleObjectSchemas(t *testing.T) {
 			"rc":             &api.ReplicationController{},
 		},
 		"../examples/spark": {
-			"namespace-spark-cluster": &api.Namespace{},
-			"spark-master-controller": &api.ReplicationController{},
-			"spark-master-service":    &api.Service{},
-			"spark-webui":             &api.Service{},
-			"spark-worker-controller": &api.ReplicationController{},
-			"zeppelin-controller":     &api.ReplicationController{},
-			"zeppelin-service":        &api.Service{},
+			"namespace-spark-cluster":   &api.Namespace{},
+			"spark-master-controller":   &api.ReplicationController{},
+			"spark-master-service":      &api.Service{},
+			"spark-ui-proxy-controller": &api.ReplicationController{},
+			"spark-ui-proxy-service":    &api.Service{},
+			"spark-worker-controller":   &api.ReplicationController{},
+			"zeppelin-controller":       &api.ReplicationController{},
+			"zeppelin-service":          &api.Service{},
 		},
 		"../examples/spark/spark-gluster": {
 			"spark-master-service":    &api.Service{},