Fix some readme and script bugs in examples (take 2).

v2: Resolve issues from comments, fix bugs in update-demo example, rename files for clarity, add turn-down steps.

v3: Add more set commands, clean up rest of env var checks.

examples/update-demo/images/build-images.sh

@@ -1,32 +0,0 @@
-#!/bin/bash
-
-# Copyright 2014 Google Inc. All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-# This script will build and push the images necessary for the demo.
-
-if (( $# != 1 )); then
-  echo "Usage: $0 <docker hub user name>"
-  exit 1
-fi
-
-DOCKER_USER=$1
-
-set -x
-
-docker build -t update-demo-base base
-docker build -t $DOCKER_USER/update-demo:kitten kitten
-docker build -t $DOCKER_USER/update-demo:nautilus nautilus
-
-docker push $DOCKER_USER/update-demo