gitlab-ci: install xwayland

The reason the Xwayland test skips is that Xwayland was not installed. We
should exercise Xwayland as well in CI, so install it.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>

.gitlab-ci.yml

@@ -5,7 +5,7 @@ variables:
   DEBIAN_VERSION: buster
   DEBIAN_EXEC: 'bash .gitlab-ci/debian-install.sh'
 
-  DEBIAN_TAG: '2019-11-04.0'
+  DEBIAN_TAG: '2019-12-13.0'
   DEBIAN_CONTAINER_IMAGE: $CI_REGISTRY_IMAGE/debian/$DEBIAN_VERSION:$DEBIAN_TAG
 
 

.gitlab-ci/debian-install.sh

@@ -56,6 +56,7 @@ apt-get -y --no-install-recommends install \
 	pkg-config \
 	python3-pip \
 	python3-setuptools \
+	xwayland \
 
 
 pip3 install --user git+https://github.com/mesonbuild/meson.git@0.49