Use default ACL for uploaded lambda code (#682)
Use default ACL for uploaded lambda code (#682)

* Use default ACL for uploaded lambda code

The "Authenticated-Read" ACL, currently set on all uploads, allows your code
to be read by all S3 users. Default behavior should be to use the permissions
implied by the bucket policy, i.e. "private".

Organizations that do not grant SetObjectAcl permissions (for fear of
data loss) will block this call.

* Add config option to make default uploads private

Per PR#682, although the default can be changed to 'private',
we should allow users to set 'authenticated-read' if they
desire.

Adds a new configuration option, payload_acl, to define this.

remind101/stacker,remind101/stacker