Elo-indexserver-client

PR:

* https://github.com/treskon/elo-indexserver-client/pull/7

Details:

* Hotfix create_folder method; used wrong bitset (mb_all) resulted in indexserver trying to assign 'freie eingabe' mask
to a folder which is not possible on some elo instances. We updated our elo testing server to be more strict on this
so we prevent this issue in the future

PR:

* https://github.com/treskon/elo-indexserver-client/pull/6

Details:

* Added configurable caching for overwrite_mask_fields (caches get_all_masks_names and get_mask_detail)
* Fix a bug that caused a severe performance issue during overwrite_mask_fields

PR:

* https://github.com/treskon/elo-indexserver-client/pull/3

Details:

* Updated to OpenAPI Spec from elo
* Added write_map_fields method to EloService

Moved from private repo to public GitHub repo.

base version