[evince] ci: Add manual pipeline to build gtk-doc using meson

[Germán Poo-Caamaño <gpoo src gnome org>]

commit 9a3ce54d72fa3e7aeba57849194f6ed7d9d60c57
Author: Germán Poo-Caamaño <gpoo gnome org>
Date:   Sat Sep 29 00:13:31 2018 -0300

    ci: Add manual pipeline to build gtk-doc using meson
    
    Added new manual pipeline to test the building Evince with
    its documentation in gtk-doc format.

 .gitlab-ci.yml | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f5596c4e..ccc11fb5 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -30,6 +30,21 @@ meson:
         - _build/meson-logs/meson-log.txt
         expire_in: 2 days
 
+meson-gtk-doc:
+    image: registry.gitlab.gnome.org/gnome/evince/master-amd64:latest
+    stage: build
+    when: manual
+
+    script:
+        - meson -Dgtk_doc=true _build
+        - ninja -C _build all libevdocument-doc libevview-doc evince-doc
+
+    artifacts:
+        when: on_failure
+        paths:
+        - _build/meson-logs/meson-log.txt
+        expire_in: 2 days
+
 gtk-doc:
     image: registry.gitlab.gnome.org/gnome/evince/master-amd64:latest
     stage: build