build the Dockerimage used in CI

.gitlab-ci.yml

-image: quantumtinkerer/research
+image: gitlab.kwant-project.org:5005/qt/adaptive
 
 test:
   script:
-    - pip install -r test-requirements.txt
-    - conda install -y -q scikit-optimize
     - py.test --verbose --cov=adaptive --cov-report term --cov-report html adaptive
   artifacts:
     paths:
@@ -18,3 +16,21 @@ authors check:
 check whitespace style:
   script: ./check_whitespace
   allow_failure: true
+
+build docker:
+  image:
+    name: gcr.io/kaniko-project/executor:debug
+    entrypoint: [""]
+  before_script:
+    - docker login -u $CI_DEPLOY_USER -p $CI_DEPLOY_PASSWORD $CI_REGISTRY
+    - export CI_REF=${CI_COMMIT_TAG:-latest}
+  script:
+    - /kaniko/executor
+      --context $CI_PROJECT_DIR
+      --dockerfile $CI_PROJECT_DIR/Dockerfile
+      --destination $CI_REGISTRY_IMAGE:$CI_REF
+  only:
+    changes:
+      - Dockerfile
+      - environment.yml
+      - test-requirements.txt