- Re-adding the ability to specify credential profile in the environment config.
- Adding init project command to help initialize a new Sceptre project.
- Adding init env command to help initialize a new Environment config.
- Adding diff command to display differences between the local and deployed
stack template.
- Fixed error message displayed for empty environments.
- Adding `environment_config` to config template rendering.
- Adding `on_failure` parameter to stack config.
- Adding automatic renewal of expired credentials when assuming IAM Roles.
- Deprecating use of `bash` hook in favour of `cmd` hook.
- Deprecating use of `asg_scheduled_actions` hook in favour of
`asg_scaling_processes` hook.
- Adding status colouring for output of describe-env command.
- Fix spelling mistakes in documentation.