Tool for management of Aptly publishes

 This tool allows one to create aptly multi-component
 publishes from YAML definition of repositories and mirrors
 .
 Features:
  - create or update publish from latest snapshots
    - it takes configuration in yaml format which defines what to publish and
      how
    - expected snapshot format is ``<name>-<timestamp>``
  - promote publish
    - use source publish snapshots to create or update another publish (eg.
      testing -> stable)
  - cleanup unused snapshots