[gimp/wip/nielsdg/add-gitlab-ci] Add a GitLab CI manifest

[Niels De Graef <nielsdg src gnome org>]

commit d94b91a57cdaebce4cec405cebee8a676765afad
Author: Niels De Graef <nielsdegraef gmail com>
Date:   Sun Jul 21 10:33:38 2019 +0200

    Add a GitLab CI manifest
    
    This manifest will allow us to run some basic checks on each commit and
    integrate build status properly into the GitLab UI. This does not need
    to contend with build.gimp.org per se: we can use the CI for Merge
    Requests to perform basic checks, while the build server does the heavy
    work.

 .gitlab-ci.yml | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
new file mode 100644
index 0000000000..ac53373dcf
--- /dev/null
+++ b/.gitlab-ci.yml
@@ -0,0 +1,14 @@
+stages:
+  - build-flatpak
+
+flatpak:master:
+  image: registry.gitlab.gnome.org/gnome/gnome-runtime-images/gnome:3.32
+  stage: build-flatpak
+  script:
+    - flatpak-builder --stop-at=gimp _build build/flatpak/org.gimp.GIMP-nightly.json
+    - flatpak build _build./autogen.sh
+    - flatpak build _build make -j8
+    - flatpak-builder --finish-only --repo=repo _build build/flatpak/org.gimp.GIMP-nightly.json
+  cache:
+    paths:
+      - .flatpak-builder/cache