[evince] gitlab-ci: Add gnome-common to CI requirements

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

commit ffd934515c0920551bf66f80c1e2424f576ccd04
Author: Germán Poo-Caamaño <gpoo gnome org>
Date:   Wed May 23 23:31:01 2018 -0400

    gitlab-ci: Add gnome-common to CI requirements

 .gitlab-ci.yml | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 49092d34..761db5a9 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -5,6 +5,9 @@ ubuntu:
     image: amd64/ubuntu:18.04
     stage: build
 
+    before_script:
+        - apt-get install -y gnome-common
+
     script:
         - ./autogen.sh --enable-debug --enable-nautilus
                        --enable-introspection