[gtk: 1/2] gitlabci: Add gtk-doc to the container image.

[Emmanuele Bassi <ebassi src gnome org>]

commit 50985d922a6c8995ac6cf9592a12d051f53c5158
Author: Jordan Petridis <jordanpetridis protonmail com>
Date:   Mon Apr 30 18:39:05 2018 +0300

    gitlabci: Add gtk-doc to the container image.

 .gitlab-ci/Dockerfile | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/.gitlab-ci/Dockerfile b/.gitlab-ci/Dockerfile
index 84005c8324..32fa7e7c62 100644
--- a/.gitlab-ci/Dockerfile
+++ b/.gitlab-ci/Dockerfile
@@ -28,6 +28,7 @@ RUN dnf -y install \
     gstreamer1-plugins-good \
     gstreamer1-plugins-bad-free-devel \
     gstreamer1-plugins-base-devel \
+    gtk-doc \
     iso-codes \
     itstool \
     json-glib-devel \