APT packaging fixes
- Adopt nightly versioning to be parsed
- Fix binary source path for release builds
Improve unstable build versioning
Use timestamp as bugfix version, as we would have the same version number in all builds until the version tag gets updated
- Add publishing automated debian package releases via Cloudsmith.io, which allows evcc to be installed and updated via `apt`
- Add nightly docker (:latest) and deb distribution
- Disable docker builds for every commit on master
- Allow nightly builds to be triggered manually
