Certbot-deployer

Changed
- Add more logging to `read_config`
- Change the key for this tool in its configuration file from `main` to `certbot_deployer`

Added
- Add new argument `--version` to print version of this tool and any plugins

Fixed
- Bring all internal cli argument names into line with their user-facing names for ease of reference in configuration file

Fixed
- Alter arg parsing to allow "required" arguments to come from the Certbot Deployer config file

Fixed
- Removed external requirement for the `scp` command, now doing SCP purely via Python

Fixed
- Fix broken command in `save` workflow step

Changed
- Switch dry run intro message from stderr to stdout

Added
- Add a new workflow step to save running config before optional sync