Sentinel Firewall logs collector version 0.3.0

Added
* support for welcome message required for newer versions of
  sentinel-proxy
* dependency on libczmq\_logc that integrates CZMQ logging with LogC
* configuration parsing for `nflog_group`, `socket` and `topic`

Changed
* minimal required version of LogC is now 0.2.0

Fixed
* CI: release description for automatic release creation