Restrict CI deploy stage to master only

.gitlab-ci.yml

@@ -90,6 +90,8 @@ deploy:latex:
     paths:
       - ${DOCS_DIRECTORY}/_build/latex/${DOCS_LATEX_NAME}.pdf
     expire_in: 6 month
+  only:
+    - master
 
 pages:
   stage: deploy
@@ -99,4 +101,6 @@ pages:
     - mv ${DOCS_DIRECTORY}/_build/html/ ${CI_PROJECT_DIR}/public/
   artifacts:
     paths:
-      - public
\ No newline at end of file
+      - public
+  only:
+    - master
\ No newline at end of file