Support actual S3 Path instead of just bucket name

[jarosser06]

To upload the new templates to S3 requires a bucket name currently for the --path flag which doesn't make a lot of sense. A path would usually suggest s3://mybucket/templates over just the name of an s3 bucket.

Support for this path would also allow for uploading templates to a subdirectory of a bucket as well. The downside is this does break the interface a little but I think there is a bigger win here.