Merge branch 'issue/correct_gitlabci_yml' into 'master'

replace explicit url in gitlab-ci.yml by internal includes

See merge request extensions/dune-vtk!4

.gitlab-ci.yml

 ---
-
 include:
-  - "https://gitlab.mn.tu-dresden.de/amdis/ci-config/raw/master/config/common/master.yml"
-  - "https://gitlab.mn.tu-dresden.de/amdis/ci-config/raw/master/jobs/common/master.yml"
+  - project: 'core/ci-config'
+    ref: master
+    file: 'config/common/master.yml'
+  - project: 'core/ci-config'
+    ref: master
+    file: 'jobs/common/master.yml'
 
 before_script:
   - . /duneci/bin/duneci-init-job