bug that delete the newest backups has been fixed

Improve performance for upload and download. Improve progress bar.

improve readme

fix Altinity#23

small refactoring

Many changes (Altinity#12)

- added commands: 'create', 'list', 'extract'
- rename commands: 'restore' to 'restore-data', 'create-tables' to 'restore-schema'
- now 'restore-schema', 'restore-data', 'upload', 'download' require backup name
- now 'create', 'restore-schema', 'restore-data' support flag '--table' specifying specific tables
- options backup_to_keep is separated for local and s3
- improve tests

improved versioning

fix bug with freeze partition on new method creation tables