Chore: 1.6.0

# [1.6.0](https://git.rwth-aachen.de/coscine/api/sts/compare/v1.5.0...v1.6.0) (2019-12-09)

### New

* Add new users to a configurable AD (coscine/issues#465) ([44f223e5](https://git.rwth-aachen.de/coscine/api/sts/commit/44f223e54a65fbf06dacb0fa2cf660a36ff7956e)), closes [coscine/issues#465](https://git.rwth-aachen.de/coscine/issues/issues/465)