[pygobject] ci: build and run tests in the gnome master flatpak runtime. Fixes #241

[Christoph Reiter <creiter src gnome org>]

commit ff1df6be4deab080fc7f249f276e37c1a4f8e152
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Sun Aug 12 21:16:10 2018 +0200

    ci: build and run tests in the gnome master flatpak runtime. Fixes #241
    
    Allow failures for now as we don't control it and can't easily react if it breaks.

 .gitlab-ci.yml             | 7 +++++++
 .gitlab-ci/test-flatpak.sh | 6 ++++++
 2 files changed, 13 insertions(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 5e899b5d..21ce5982 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -116,3 +116,10 @@ xenial-i386-py2:
   image: registry.gitlab.gnome.org/gnome/pygobject/old:v2
   script:
    - bash -x ./.gitlab-ci/test-docker-old.sh
+
+gnome-master:
+  allow_failure: true
+  stage: build_and_test
+  image: registry.gitlab.gnome.org/gnome/gnome-runtime-images/gnome:master
+  script:
+    - xvfb-run -a flatpak run --filesystem=host --share=network --socket=x11 --command=bash 
org.gnome.Sdk//master -x .gitlab-ci/test-flatpak.sh
diff --git a/.gitlab-ci/test-flatpak.sh b/.gitlab-ci/test-flatpak.sh
new file mode 100755
index 00000000..3e3a9923
--- /dev/null
+++ b/.gitlab-ci/test-flatpak.sh
@@ -0,0 +1,6 @@
+#!/bin/bash
+
+set -e
+
+python3 -m pip install --user pytest
+python3 setup.py test