Mdbackup

- `fix`: S3 cleanup was not working
- `fix`: running `mdbackup cleanup` with cloud providers in secret backends did not load them

Fixes 64 once for all

- `fix`: mysql backup using docker fails if user is set (64)
- `docs`: add missing `cpus` setting in zstd (65)
- `docs`: change cypher to encrypt key in config (66)
- `fix,docs`: add cypher and cipher for gpg action (67)
- `fix`: compress algorithm in gpg if not set, fails (68)
- `feature`: added cpus option for compress in cloud upload
- `fix`: upload fails if backupsPath in config uses relative paths
- `fix`: files will now be encrypted/compressed following configuration when uploaded

New Features

- Added support for `.yaml`/`.yml` config files.
- Configuration `-c` option now expects a folder with a config file and tasks.
- File secrets backend will default to `${config_folder}/secrets` as `basePath` instead of fail.
- Implemented actions and tasks.
- Backups will have a *backup manifest* with information about what has been run and what files/folders have been generated from each *task* - useful for a future restoring functionality.
- Added config validations using json schema.
- When uploading to cloud storage, compress and/or encrypt steps are done using actions implementation (avoiding duplicated code).
- Implemented *unactions* system for the future restore mode
- Uploading backups will now keep some folder structure and will only archive folders that were result of a task. This will simplify restore operations in any sense :)
- Added tests :)

Cool bits

- Tool can be found in [PyPi](https://pypi.org/project/mdbackup/): go and install it using `pip install mdbackup` 😄
- Deployed documentation to GitHub Pages: [mdbackup.majorcadevs.com](https://mdbackup.majorcadevs.com/)

Fixes

- Improvements and bug fixes on S3 and B2 upload, including random `KeyError` exceptions.
- Fixed issues when uploading files to S3/B2 that will contain duplicated prefix keys or rogue `/` characters.
- Fixed crash when using python 3.6 (we want to make it fully compatible with that version).

Breaking changes

- Configuration switch `-c` expects folder not a config file.
- Backup logic is now done using *actions* and *tasks* which are defined using `yaml` files inside `${config_folder}/tasks`.
- `compression`, `encrypt` and `storages` are now inside a `cloud` parent element.
- `storages` is called now `providers`.
- `ftp` and `ftps` providers now have `port` setting.
- `sftp` changed the setting from `disableHostKeys` to `enableHostKeys`.
- Rework commands: they are now friendlier and accept different arguments depending on the command ([check out documentation](https://mdbackup.majorcadevs.com/dev/arguments/) for more)

Cool new features for this 0.4.0 version, which if everything is working, will soon go out :D

- Rework commands: they are now friendlier and accept different arguments depending on the command ([check out documentation](https://mdbackup.majorcadevs.com/dev/arguments/) for more)
- Added support for referencing variables in `env` sections and environment variables ([go to Tasks documentation to see more](https://mdbackup.majorcadevs.com/dev/tasks/#referring-to-secrets-in-env-sections))
- Tasks can receive settings for when the result is being uploaded to the cloud. At the moment, the only option available is to ignore the file/folder so it won't upload (go to the Tasks documentation too)
- Start publishing the tool in [PyPi](https://pypi.org/project/mdbackup/): go and install it using `pip install mdbackup` 😄

And also some fixes:
- Fixed issues when uploading files to S3/B2 that will contain duplicated prefix keys or rogue `/` characters
- Fixed crash when using python 3.6 (we want to make it fully compatible with that version)
- Fixed failure when running a command using string as parameter

Fixes a bug introduced in the last beta that made `complete` and `check-config` modes not to work.