Allow multiple deployments of the same transformation output

[mmunozba]

Currently, the output of a CloudFormation transformation can only be deployed once.
This is because the stack and bucket names are set during transformation. Each CloudFormation stack and S3 Bucket on AWS must have a unique name. So, if another deployment with the same names is attempted, the deployment fails due to them already being in use.

To fix this, we would have to move the bucket and stack name creation to the deployment phase of our Plugin. Each deployment would get a unique stack and bucket name at deployment time.