v0.4.0

Update to `stacks`. Add `import` to all configs. Remove hardcoded settings. Add Terraform S3 backend generation @aknysh (#6)

what

• Update to stacks (instead of environment/stage)
• Update to components (instead of projects)
• Add import to all configs
• Remove hardcoded settings
• Add Terraform S3 backend generation
• Simplify

why

• Use stacks instead of environment/stage to define configurations - this will allow arbitrary naming the stacks and not tying them to env/stage, as well as separation of stacks for the same environment/stage into different files (e.g. terraform config in one file, helmfiles config in another), or separation of stacks by AWS resources
• Add import to YAML stack configs - allow automatically importing global-globals and stack-globals into each configuration
• Remove hardcoded settings - make the CLI generic (no hardcoded namespaces, regions, IAM roles, etc.)
• Add (and simplify) the CLI commands to generate Terraform S3 backend configs for each Terraform component