Automatically add robots.txt

[gkpty]

When deploying a dev/test bucket, add a robots.txt to tell google to crawl none.

User-agent: *
Disallow: /

When deploying a production bucket change robots.txt to:

User-agent: *
Allow: /

Only add a robots.txt file if one doesnt already exist.

Add a in the upload method that will allow/disallow user agents depending if its prod/test