gitlab-ci: Deploy pages from the apertis/v2019dev0 branch

We are moving to per-release branches in every repository and this one is
no exception. :)

Signed-off-by: Emanuele Aina <emanuele.aina@collabora.com>

.gitlab-ci.yml

@@ -8,7 +8,7 @@ test:
     paths:
       - test
   except:
-    - master
+    - apertis/v2019dev0
 
 pages:
   stage: deploy
@@ -18,4 +18,4 @@ pages:
     paths:
       - public
   only:
-    - master
+    - apertis/v2019dev0