Chore: 1.9.0

# [1.9.0](https://git.rwth-aachen.de/coscine/cs/database/compare/v1.8.0...v1.9.0) (2019-11-11)

### New

* Add the English version of the DFG Fachsystematik to the DB (coscine/issues#431) ([33ab7837](https://git.rwth-aachen.de/coscine/cs/database/commit/33ab7837633b508f484823bf1d2e26a2e4244cb4)), closes [coscine/issues#431](https://git.rwth-aachen.de/coscine/issues/issues/431)