feat(state): improved stateful mode, Redis and S3 are now supported (#9)

* feat(state): improved stateful mode, Redis and S3 are now supported

fix(etl): fixed possible new state bug with seekable issue list (gene…

…rator)

fix(helpers): hot fix for to_snake_case func - added cyrillic support

feat: added support for extending the TrackerIssue model

Merge pull request #5 from akimrx/changelog

feat: ETL for issue changelog

fixed clickhouse client, bump version

Merge pull request #3 from akimrx/fix-workdays-metrics

fix(metrics): fixed bug with workdays metrics, replaced lib

init