tf-runner is a wrapper around terraform that makes running terraform in multiple environments and storing the remote state in S3 easier.
tf-runner expects a directory named environments with a directory for each environment in it. The terraform commands will run in the appropriate environment directory based on the specified env option.
For e.g. running tf --env staging apply would run terraform's apply wrapper inside ./environments/staging.
tf bootstrap will create a versioned S3 bucket to store terraform's remote state in.