Merge branch 'TMSS-221' of https://git.astron.nl/ro/lofar into TMSS-221

Docker/lofar-ci/Dockerfile_ci_sas

SAS/TMSS/src/remakemigrations.py

SAS/TMSS/src/tmss/tmssapp/migrations/0001_initial.py

SAS/TMSS/src/tmss/tmssapp/migrations/0002_populate.py

SAS/TMSS/src/tmss/tmssapp/models/specification.py

SAS/TMSS/src/tmss/tmssapp/populate.py

SAS/TMSS/src/tmss/tmssapp/serializers/specification.py

SAS/TMSS/src/tmss/tmssapp/viewsets/specification.py

SAS/TMSS/src/tmss/urls.py

SAS/TMSS/test/t_tmssapp_specification_REST_API.py

SAS/TMSS/test/tmss_test_data_django_models.py

SAS/TMSS/test/tmss_test_data_rest.py