* Migrate Elasticsearch to backend plugin SDK
* Fix linting
* Move away from Convey!
* Rebase commit
* Small logger fix
* Fixes according to reviewer's comments
* Fixes according to reviewer's comments
* Fixes according to reviewer's comments
* More cleanup
* Move things around - small refactoring
* Fix typo
* Update calculator - add tests
* Fixes according to reviewer's comments
When weekly index pattern is used, indices names contain single digit week number for week 1-9
This fix makes sure indice names always contain 2 digit week number for weekly pattern