add regex validation to pre-config buckets; update README cli update instructions

Author: Andrews

README.md

@@ -5,7 +5,7 @@ aws-serverless-developer-portal is a reference implementation for a developer po
 It also optionally supports subscription/unsubscription through a SaaS product offering through the AWS Marketplace.
 
 ## Setup
-First, ensure you have the latest AWS CLI installed (eg. `pip install --upgrade awscli`) http://docs.aws.amazon.com/cli/latest/userguide/installing.html.
+First, ensure you have the latest AWS CLI installed http://docs.aws.amazon.com/cli/latest/userguide/installing.html.
 
 ```js
 npm install

pre-configure.js

@@ -18,16 +18,18 @@ const questions = [{
 }, {
     name: 'artifactsS3BucketName',
     message: 'S3 bucket for artifacts such as Lambda package and Swagger file (will be created if it doesn\'t exist):',
-    type: 'input'
+    type: 'input',
+    validate: value => /^[a-zA-Z0-9.\-_]{1,255}/.test(value)
 }, {
     name: 'clientS3BucketName',
     message: 'S3 bucket for website (will be created; do not provide existing bucket):',
-    type: 'input'
+    type: 'input',
+    validate: value => /^[a-zA-Z0-9.\-_]{1,255}/.test(value)
 }, {
     name: 'cloudFormationStackName',
     message: 'CloudFormation stack name:',
     type: 'input',
-    default: 'DevPortalStack'
+    default: 'Dev Portal Stack'
 }, {
     name: 'apiGatewayApiName',
     message: 'API name:',