Change CI configuration to build non-master branches in a test directory for testing/preview

.gitlab-ci.yml

@@ -1,9 +1,12 @@
 image: alpine
 
+before_script:
+- apk --no-cache add make py3-setuptools python3-dev
+- python3 -m pip install sphinx sphinx_rtd_theme
+
 pages:
+  stage: deploy
   script:
-  - apk --no-cache add make py3-setuptools python3-dev
-  - python3 -m pip install sphinx sphinx_rtd_theme
   - cd manual
   - make html
   - mv build/html/ ../public/
@@ -12,3 +15,15 @@ pages:
     - public
   only:
   - master
+
+test:
+  stage: test
+  script:
+  - cd manual
+  - make html
+  - mv build/html/ ../test/
+  artifacts:
+    paths:
+    - test
+  except:
+  - master