Test sphinx generation on every commit

Produces a downloadable artifact

.gitlab-ci.yml

@@ -66,7 +66,7 @@ k8s-ticket-testing-deploy:
     name: staging
     url: https://ticket-testing.lca2018.org
 
-pages:
+.docs_template: &sphinx
   image: alpine
   script:
   - apk --no-cache add py2-pip python-dev make
@@ -78,8 +78,15 @@ pages:
   artifacts:
     paths:
     - public
+
+pages:
+  <<: *sphinx
   only:
   - master
   environment:
     name: docs
     url: https://lca2018.gitlab.io/symposion_app/
+
+test_sphinx:
+  <<: *sphinx
+  stage: test