Delete .gitlab-ci.yml

.gitlab-ci.yml

-# requiring the environment of python
-image: python:3.9-buster
-
-before_script:
-  - pip install -r requirements.txt
-
-test:
-  stage: test
-  script:
-    - jupyter-book build . # build to public path
-  only:
-    - branches # this job will affect every branch except 'master'
-  except:
-    - master
-    
-# the 'pages' job will deploy and build your site to the 'public' path
-pages:
-  stage: deploy
-  script:
-    - jupyter-book build . # build to public path
-  artifacts:
-    paths:
-      - _build
-    expire_in: 10 mins
-  only:
-    - master # this job will affect only the 'master' branch